Handbook of Esports Medicine: Clinical Aspects of Competitive Video Gaming 3030736091, 9783030736095

Citation preview

Handbook of Esports Medicine Clinical Aspects of Competitive Video Gaming

Lindsey Migliore · Caitlin McGee · Melita N. Moore   Editors

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Handbook of Esports Medicine

Lindsey Migliore  •  Caitlin McGee Melita N. Moore Editors

Handbook of Esports Medicine Clinical Aspects of Competitive Video Gaming

Editors Lindsey Migliore GamerDoc Washington, DC USA

Caitlin McGee 1HP Washington, DC USA

Melita N. Moore Level Up Sports Medicine Sacramento, CA USA

ISBN 978-3-030-73609-5    ISBN 978-3-030-73610-1 (eBook) https://doi.org/10.1007/978-3-030-73610-1 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Dedicated to Stella, and bossy girls.

Foreword

In my tenure as chief executive of Evil Geniuses, our grounding beliefs that gaming should be ubiquitous, and thus we offer a seat at the table for all the best esports athletes, go hand in hand with physical and mental wellness. Also, in my tenure in esports, it never failed to surprise me how that idea, when broached with others in the space, received a response as if it were iconoclastic and novel. But health and wellness for athletes, even player athletes, is not a radical idea. When you devote your entire livelihood to a dream and a demanding activity, you must be holistically prepared and supported to execute at the highest level. However, until now, our player athletes have been failed by the industry and infrastructure, as the support around the legitimacy of holistic wellness, was insufficient and non-existent. When I was approached by Dr. Migliore about the creation of an esports medicine handbook, I could only feel relief  – like a large weight had been lifted from my back. But let me clarify – relief not because of pride of inclusion, or of the opportunity to showcase my (mediocre) writing skills, but relief in the fact that tenured, brilliant, and passionate medical professionals had taken the time and diligence to tirelessly collaborate, think through, and put forth a much-overdue source of knowledge on esports health and medicine. When developing competitive esports champions, I remember entering the space a few years ago to find myself bewildered at the lack of robust and holistic support for these player athletes. I use “athlete” on purpose – mental, physical, and emotional health are vii

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all necessary for top tier competitive play. Yet it was an underserved and underdeveloped sector of the competitive ecosystem. But this is ludicrous, as player churn is high due to injury at a relatively young age compared to traditional sports – eye strain, carpal tunnel, psychological lack of support, the list goes on – we all do ourselves a disservice to the development of the esports space. We also do ourselves a horrendous disservice to the humans who have put their all into their sport and have sacrificed their future to excel today. While most people know myself as the esports CEO that heralded from private equity, what most people do not see is the esports CEO that fell in love with non-traditional competitive sports since my teen years. In an earlier life, I coached Tae Kwon Do. I lived and breathed the importance of instilling mental and physical wellness – and toughness – into those as young as four. I lived the reality of how one’s sport can be their escape, their opportunity, their life. I see esports as no different – and the focus, seriousness, and passion carry through. Martial arts created me, and the focus on mental and physical coaching was paramount throughout my life. This focus carries over to me as a team owner, as I want the best players to compete at their fullest, and when they leave my team – as they all must one day – they leave as healthy and ethical humans, prepared for what comes next. My player athletes are not assets to me, for lifting trophies, or building brands. They are unique and diverse human beings, who have trusted me to help them develop, grow, and fulfill their ambitions. They come from all walks of life, all genders, all sexual orientations, all creeds, and for me to be nimble in their holistic support is an absolute must. But I am not a medical expert, and the resources for me to do this did not exist. This is known by your wonderful authors, a diverse, intelligent, and progressive group of doctors, physical therapists, personal trainers, and researchers, who deeply know the interconnectedness of the human body, mind, and output. Their sacrifice and focus to provide a guiding text that will create a sturdy foundation for the prosperity of the esports industry and their athletes should matter to more than just team owners.

Foreword

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Fans should rejoice that their beloved players and personalities are getting the support they need to live a full and safe career. Industry professionals and the competitive ecosystem should celebrate as the mass-acceptance of the legitimacy and importance of esports and its athletes expands. And for the curious mind, rejoice that you get to observe progress being made in the future of a global sustainable entertainment and sport. Physical and mental health cannot be overlooked, and I am grateful to have the opportunity to introduce you to a lynchpin and industry-revolutionizing text. Nicole LaPointe Jameson Evil Geniuses Seattle, WA, USA

Preface

Esports medicine is a field in its infancy. Competitive gaming has exponentially grown in the past years, with revenues reaching billions. Athletes, motivated by the idea of playing video games for a real salary, “grind” for excessive hours to turn their dream into reality. Without adequate support or informed healthcare professionals, most are forced into retirement just after reaching their twenties. This book serves as an introduction to the field of esports, as well as to the specific injuries and disorders that affect patients with this unique lifestyle. Practitioners will not only be educated what exactly competitive gaming truly is but also each ailment that corresponds to the playstyle. As with any origin story, the field of esports medicine still has an incredible future ahead of it, and much to learn. Current data and recommendations are based on case and observational studies, or extrapolated from similar populations. Those who wish to pursue this path must do so with an open, inquisitive, and creative mind, as well as an understanding that this is a field unlike any other. Washington, DC, USA Washington, DC, USA Sacremento, CA, USA

Lindsey Migliore Caitlin McGee Melita N. Moore

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Acknowledgments

This would not have been possible without the tireless support of our friends and families. It was written well past office hours, late into the night, and during a pandemic. Thank you to Amber for the never-ending encouragement and limitless patience, Marken for always making things look beautiful, and Sarah for bringing this over the finish line. Thank you to Craig for your confidence, reassurance, and spreadsheets. Thank you to our amazing contributing authors for their hard work, independence, and commitment to excellence. To the team at Springer, specifically Kristopher Spring and Richard Lansing, thank you for your courage to be the first. We’re thrilled to be able to share our knowledge, experience, and passion with all who want to learn.

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Contents

1 What Is Esports? The Past, Present, and Future of Competitive Gaming��������������������������������������������������  1 Lindsey Migliore 1.1 Introduction������������������������������������������������������������  1 1.2 History��������������������������������������������������������������������  2 1.3 Console Versus Computer Gaming ������������������������  5 1.3.1 Console Gaming�����������������������������������������  5 1.3.2 Computer Gaming��������������������������������������  6 1.3.2.1 Personal Computer (PC) Gaming, Mouse and Keyboard Gaming������������������������  6 1.4 Esports Genres��������������������������������������������������������  7 1.4.1 First-Person Shooter�����������������������������������  8 1.4.1.1 Call of Duty, Overwatch, Counter-Strike: Global Offensive, Halo, Rainbow 6 Siege������������������������������������������  8 1.4.2 Battle Royale����������������������������������������������  9 1.4.2.1 PlayerUnknown’s Battlegrounds (PUBG), Fortnite, Apex Legends, H1Z1, Call of Duty: Warzone������  9 1.4.3 Real-Time Strategy ������������������������������������ 10 1.4.3.1 Starcraft, Warcraft������������������������ 10 1.4.4 Multiplayer Online Battle Arena���������������� 11 1.4.4.1 Defense of the Ancients (Dota), League of Legends (LoL), Smite�������������������������������������������� 11 xv

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1.4.5 Fighting������������������������������������������������������ 12 1.4.5.1 Street Fighter (SFV), Tekken, Mortal Kombat, Dragon Ball FighterZ, Injustice, Skullgirls������ 12 1.4.6 Digital Collectible Card Game������������������� 12 1.4.6.1 Hearthstone���������������������������������� 12 1.4.7 Sports Simulation���������������������������������������� 13 1.4.7.1 NBA2K, NHL, Rocket League, FIFA ������������������������������ 13 1.5 Competitions ���������������������������������������������������������� 13 1.6 Video Game Live Streaming���������������������������������� 14 1.7 Conclusion�������������������������������������������������������������� 15 References������������������������������������������������������������������������ 15 2 Upper Extremity Disorders in Esports������������������������ 17 Lindsey Migliore and Kristen Beckman 2.1 General�������������������������������������������������������������������� 17 2.1.1 Anatomy������������������������������������������������������ 18 2.1.2 Evaluation �������������������������������������������������� 19 2.1.2.1 History Taking������������������������������ 20 2.1.2.2 Physical Examination������������������ 22 2.1.2.3 Imaging���������������������������������������� 25 2.1.3 Treatment���������������������������������������������������� 27 2.1.3.1 Therapeutic Modalities���������������� 27 2.1.3.2 Rehabilitation������������������������������ 28 2.1.3.3 Pharmacology������������������������������ 28 2.1.3.4 Interventions�������������������������������� 28 2.2 Hand and Wrist ������������������������������������������������������ 29 2.2.1 Radial Styloid Tenosynovitis���������������������� 29 2.2.1.1 Overview�������������������������������������� 29 2.2.1.2 Pathogenesis�������������������������������� 29 2.2.1.3 Presentation���������������������������������� 30 2.2.1.4 Diagnosis������������������������������������� 30 2.2.1.5 Treatment ������������������������������������ 32 2.2.2 Intersection Syndrome�������������������������������� 33 2.2.2.1 Overview�������������������������������������� 33 2.2.2.2 Pathogenesis�������������������������������� 33

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2.2.2.3 Presentation���������������������������������� 34 2.2.2.4 Diagnosis������������������������������������� 34 2.2.2.5 Treatment ������������������������������������ 34 2.2.3 Extensor Carpi Ulnaris Tendonitis�������������� 37 2.2.3.1 Overview�������������������������������������� 37 2.2.3.2 Pathogenesis�������������������������������� 37 2.2.3.3 Presentation���������������������������������� 39 2.2.3.4 Diagnosis������������������������������������� 39 2.2.3.5 Treatment ������������������������������������ 41 2.2.4 Median Neuropathy at the Wrist���������������� 41 2.2.4.1 Overview�������������������������������������� 42 2.2.4.2 Pathogenesis�������������������������������� 42 2.2.4.3 Presentation���������������������������������� 43 2.2.4.4 Diagnosis������������������������������������� 43 2.2.4.5 Treatment ������������������������������������ 46 2.2.5 Triangular Fibrocartilage Complex Injury���������������������������������������������������������� 47 2.2.5.1 Overview�������������������������������������� 47 2.2.5.2 Pathogenesis�������������������������������� 47 2.2.5.3 Presentation���������������������������������� 47 2.2.5.4 Diagnosis������������������������������������� 48 2.2.5.5 Treatment ������������������������������������ 48 2.2.6 Thumb Carpometacarpal Arthritis�������������� 49 2.2.6.1 Overview�������������������������������������� 49 2.2.6.2 Pathogenesis�������������������������������� 49 2.2.6.3 Presentation���������������������������������� 49 2.2.6.4 Diagnosis������������������������������������� 49 2.2.6.5 Treatment ������������������������������������ 50 2.2.7 Radial Sensory Neuritis������������������������������ 51 2.2.7.1 Overview�������������������������������������� 51 2.2.7.2 Pathogenesis�������������������������������� 51 2.2.7.3 Presentation���������������������������������� 52 2.2.7.4 Diagnosis������������������������������������� 52 2.2.7.5 Treatment ������������������������������������ 53 2.3 Elbow���������������������������������������������������������������������� 54 2.3.1 Ulnar Neuropathy��������������������������������������� 54 2.3.1.1 Overview�������������������������������������� 54

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2.3.1.2 Pathogenesis�������������������������������� 54 2.3.1.3 Presentation���������������������������������� 55 2.3.1.4 Diagnosis������������������������������������� 57 2.3.1.5 Treatment ������������������������������������ 60 2.3.2 Lateral Epicondylitis���������������������������������� 61 2.3.2.1 Overview�������������������������������������� 61 2.3.2.2 Pathogenesis�������������������������������� 61 2.3.2.3 Presentation���������������������������������� 61 2.3.2.4 Diagnosis������������������������������������� 62 2.3.2.5 Treatment ������������������������������������ 63 2.3.3 Olecranon Bursitis�������������������������������������� 65 2.3.3.1 Overview�������������������������������������� 65 2.3.3.2 Pathogenesis�������������������������������� 65 2.3.3.3 Presentation���������������������������������� 65 2.3.3.4 Diagnosis������������������������������������� 65 2.3.3.5 Treatment ������������������������������������ 66 References������������������������������������������������������������������������ 66 3 Neck and Back Disorders in Esports���������������������������� 71 Lindsey Migliore and Caitlin McGee 3.1 Overview���������������������������������������������������������������� 71 3.1.1 Anatomy������������������������������������������������������ 72 3.1.2 Evaluation �������������������������������������������������� 74 3.1.2.1 History Taking������������������������������ 74 3.1.2.2 Physical Examination������������������ 75 3.1.2.3 Diagnostic Imaging���������������������� 75 3.1.3 Treatment���������������������������������������������������� 77 3.1.3.1 Therapeutic Modalities���������������� 77 3.1.3.2 Rehabilitation������������������������������ 77 3.1.3.3 Pharmacological Management���� 78 3.1.3.4 Interventions�������������������������������� 78 3.2 Myofascial Conditions�������������������������������������������� 79 3.2.1 Overview���������������������������������������������������� 79 3.2.2 Pathogenesis������������������������������������������������ 79 3.2.3 Presentation������������������������������������������������ 80 3.2.4 Diagnosis���������������������������������������������������� 80 3.2.5 Treatment���������������������������������������������������� 81

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3.2.5.1 Therapeutic Modalities���������������� 81 3.2.5.2 Pharmacological Management���� 81 3.2.5.3 Interventions�������������������������������� 81 3.3 Thoracic Outlet Syndrome�������������������������������������� 82 3.3.1 Overview���������������������������������������������������� 82 3.3.2 Pathogenesis������������������������������������������������ 83 3.3.3 Presentation������������������������������������������������ 83 3.3.4 Diagnosis���������������������������������������������������� 84 3.3.5 Treatment���������������������������������������������������� 84 3.4 Postural Dysfunctions �������������������������������������������� 85 3.4.1 Forward Head Posture�������������������������������� 85 3.4.1.1 Overview�������������������������������������� 85 3.4.1.2 Pathogenesis�������������������������������� 86 3.4.1.3 Presentation���������������������������������� 87 3.4.1.4 Diagnosis������������������������������������� 87 3.4.1.5 Treatment ������������������������������������ 88 3.4.2 Excessive Thoracic Kyphosis��������������������� 90 3.4.2.1 Overview�������������������������������������� 90 3.4.2.2 Pathogenesis�������������������������������� 90 3.4.2.3 Presentation���������������������������������� 90 3.4.2.4 Diagnosis������������������������������������� 90 3.4.2.5 Treatment ������������������������������������ 91 3.4.3 Limited Lumbar Lordosis �������������������������� 92 3.4.3.1 Overview�������������������������������������� 92 3.4.3.2 Pathogenesis�������������������������������� 92 3.4.3.3 Presentation���������������������������������� 93 3.4.3.4 Diagnosis������������������������������������� 93 3.4.3.5 Treatment ������������������������������������ 93 3.5 The Spine���������������������������������������������������������������� 94 3.5.1 Spondylosis������������������������������������������������ 94 3.5.1.1 Overview�������������������������������������� 94 3.5.1.2 Pathogenesis�������������������������������� 95 3.5.1.3 Presentation���������������������������������� 96 3.5.1.4 Diagnosis������������������������������������� 97 3.5.1.5 Treatment ������������������������������������ 99 3.5.2 Intervertebral Disc Disease ������������������������100

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3.5.2.1 Overview��������������������������������������100 3.5.2.2 Pathogenesis��������������������������������101 3.5.2.3 Presentation����������������������������������102 3.5.2.4 Diagnosis�������������������������������������103 3.5.2.5 Treatment ������������������������������������103 3.5.3 Radiculopathy ��������������������������������������������105 3.5.3.1 Overview��������������������������������������105 3.5.3.2 Pathogenesis��������������������������������105 3.5.3.3 Presentation����������������������������������106 3.5.3.4 Diagnosis�������������������������������������107 3.5.3.5 Treatment ������������������������������������112 References������������������������������������������������������������������������114 4 Lower Extremity Disorders in Esports������������������������119 Caitlin McGee 4.1 General��������������������������������������������������������������������119 4.1.1 Anatomy������������������������������������������������������120 4.1.2 Evaluation ��������������������������������������������������120 4.1.2.1 History Taking������������������������������121 4.1.2.2 Physical Examination������������������122 4.1.3 Treatment����������������������������������������������������124 4.1.3.1 Therapeutic Modalities����������������124 4.1.3.2 Rehabilitation������������������������������124 4.1.3.3 Pharmacology������������������������������124 4.1.3.4 Interventions��������������������������������125 4.2 Deep Vein Thrombosis��������������������������������������������125 4.2.1 Overview����������������������������������������������������125 4.2.2 Pathogenesis������������������������������������������������125 4.2.3 Presentation������������������������������������������������126 4.2.4 Diagnosis����������������������������������������������������127 4.2.5 Treatment����������������������������������������������������128 4.2.5.1 Prevention������������������������������������128 4.2.5.2 Intervention����������������������������������128 4.3 Lower Crossed Syndrome��������������������������������������129 4.3.1 Overview����������������������������������������������������129 4.3.2 Pathogenesis������������������������������������������������129 4.3.3 Presentation������������������������������������������������129

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4.3.4 Diagnosis����������������������������������������������������130 4.3.5 Treatment����������������������������������������������������130 4.4 Proximal Hamstring Tendinopathy ������������������������131 4.4.1 Overview����������������������������������������������������131 4.4.2 Pathogenesis������������������������������������������������132 4.4.3 Presentation������������������������������������������������132 4.4.4 Diagnosis����������������������������������������������������132 4.4.5 Treatment����������������������������������������������������133 4.5 Piriformis Syndrome����������������������������������������������134 4.5.1 Overview����������������������������������������������������134 4.5.2 Pathogenesis������������������������������������������������135 4.5.3 Presentation������������������������������������������������135 4.5.4 Diagnosis����������������������������������������������������136 4.5.4.1 Physical Examination������������������136 4.5.4.2 Imaging and Diagnostics�������������137 4.5.5 Treatment����������������������������������������������������137 4.6 Sacroiliac Joint Pathology��������������������������������������138 4.6.1 Overview����������������������������������������������������138 4.6.2 Pathogenesis������������������������������������������������138 4.6.3 Presentation������������������������������������������������139 4.6.4 Diagnosis����������������������������������������������������139 4.6.4.1 Physical Examination������������������139 4.6.4.2 Imaging����������������������������������������140 4.6.5 Treatment����������������������������������������������������141 4.7 Compressive Neuropathies of the Lower Extremity����������������������������������������������������������������141 4.7.1 General��������������������������������������������������������141 4.7.1.1 Overview��������������������������������������141 4.7.1.2 Pathogenesis��������������������������������141 4.7.1.3 Diagnosis�������������������������������������142 4.7.1.4 Treatment ������������������������������������142 4.7.2 Common Peroneal Nerve����������������������������143 4.7.2.1 Overview��������������������������������������143 4.7.2.2 Presentation����������������������������������143 4.7.2.3 Diagnosis�������������������������������������143 4.7.2.4 Treatment ������������������������������������144

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4.7.3 Sciatic Nerve����������������������������������������������144 4.7.3.1 Overview��������������������������������������144 4.7.3.2 Presentation����������������������������������144 4.7.3.3 Diagnosis�������������������������������������145 4.7.3.4 Treatment ������������������������������������145 4.7.4 Femoral Nerve��������������������������������������������145 4.7.4.1 Overview��������������������������������������145 4.7.4.2 Presentation����������������������������������146 4.7.4.3 Diagnosis�������������������������������������146 4.7.4.4 Treatment ������������������������������������146 References������������������������������������������������������������������������147 5 The Ergonomics of Esports ������������������������������������������151 Caitlin McGee 5.1 Neutral Posture��������������������������������������������������������151 5.1.1 Head and Neck��������������������������������������������151 5.1.2 Trunk and Arms������������������������������������������151 5.1.3 Lower Extremities��������������������������������������152 5.2 Gaming Categories��������������������������������������������������153 5.3 Peripherals��������������������������������������������������������������153 5.3.1 Monitor ������������������������������������������������������153 5.3.2 Mouse����������������������������������������������������������154 5.3.3 Keyboard����������������������������������������������������157 5.3.4 Console Controller��������������������������������������158 5.3.4.1 Gamepad Controller��������������������158 5.3.4.2 Sticks��������������������������������������������162 5.3.5 Phone and Tablet����������������������������������������163 References������������������������������������������������������������������������164 6 Nutrition for the Video Gamer�������������������������������������167 Lauren Trocchio 6.1 Introduction������������������������������������������������������������167 6.2 Basic Esports Physiology and the Role of Nutrition��������������������������������������������������������������167 6.2.1 Physicality��������������������������������������������������168 6.2.2 Cognition����������������������������������������������������169 6.3 General Nutrition����������������������������������������������������171 6.3.1 Macronutrients��������������������������������������������171

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6.3.2 Micronutrients��������������������������������������������172 6.4 Daily Fueling����������������������������������������������������������172 6.5 Fueling Timing��������������������������������������������������������175 6.6 Supplements������������������������������������������������������������180 6.6.1 Stimulants ��������������������������������������������������180 6.6.2 Nootropics��������������������������������������������������181 6.6.3 Vision Health����������������������������������������������181 6.6.4 Supplement Safety��������������������������������������182 6.7 Special Considerations��������������������������������������������182 6.8 Summary ����������������������������������������������������������������183 References������������������������������������������������������������������������184 7 The Psychology of Digital Games ��������������������������������187 Rachel Kowert and Christopher Ferguson 7.1 Introduction������������������������������������������������������������187 7.2 The Rise of the Video Game Panic ������������������������188 7.3 Behavioral and Cognitive Impact of Digital Games ��������������������������������������������������������189 7.4 Aggression and Violent Crime��������������������������������190 7.5 Addiction����������������������������������������������������������������191 7.6 Impact on Psychological Well-Being����������������������195 7.7 Skill Development��������������������������������������������������195 7.8 Concluding Thoughts����������������������������������������������196 References������������������������������������������������������������������������196 8 Esports Mental Performance����������������������������������������201 Carl Daubert 8.1 Esports Performance Coaches��������������������������������201 8.2 Mental Performance Basics������������������������������������202 8.2.1 Imagery ������������������������������������������������������203 8.2.2 IZOF������������������������������������������������������������205 8.2.3 Confidence��������������������������������������������������207 8.2.4 Goal Setting������������������������������������������������209 8.3 The Future of Esports Performance Coaching��������211 References������������������������������������������������������������������������211 9 Prevention of Esports Injuries��������������������������������������213 Lindsey Migliore 9.1 Introduction������������������������������������������������������������213

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9.1.1 The Problem of Presentation����������������������214 9.1.2 Injury Culture����������������������������������������������215 9.1.3 Role of the Healthcare Provider������������������216 9.2 The Impact of Injury ����������������������������������������������217 9.2.1 Financial Consequences������������������������������219 9.2.2 Physical Health Complications ������������������220 9.2.2.1 Acute Tendon Injuries������������������220 9.2.2.2 Osteoarthritis��������������������������������220 9.3 Understanding Esports Injuries������������������������������221 9.3.1 Fatigue��������������������������������������������������������222 9.3.1.1 Causes of Fatigue������������������������222 9.3.1.2 Effect of Fatigue��������������������������222 9.3.1.3 Fatigue Protocols ������������������������223 9.3.2 Biomechanics and Biodynamics of Esports����������������������������������������������������224 9.3.3 Development of Esports-Specific Fatigue Protocols����������������������������������������225 9.3.4 Injury Prevention Model Development������226 9.3.4.1 van Mechelen Model��������������������226 9.3.4.2 Translating Research into the Injury Prevention Practice Framework ����������������������������������227 9.3.4.3 Reach Efficacy Adoption Implementation Maintenance Framework ����������������������������������228 9.4 Sports Injury Prevention Models����������������������������228 9.4.1 Training������������������������������������������������������229 9.4.1.1 Flexibility and Stretching������������229 9.4.1.2 Strengthening ������������������������������231 9.4.1.3 Additional Considerations ����������232 9.4.2 Rule Modification ��������������������������������������233 9.4.3 Equipment Recommendations��������������������234 9.5 Implementation and Adherence������������������������������234 9.6 Final Thoughts��������������������������������������������������������236 References������������������������������������������������������������������������237

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10 Esports Cultural Competence��������������������������������������241 Caitlin McGee 10.1 Gaming Versus Esports Culture����������������������������241 10.2 Professional Development������������������������������������243 10.3 Current Practice Routines ������������������������������������245 10.4 Caveat��������������������������������������������������������������������246 References������������������������������������������������������������������������247 Index�������������������������������������������������������������������������������������� 249

About the Editors

Lindsey Migliore  is a board certified physician in the field of physical medicine and rehabilitation. She has dedicated her career to advancing the field of esports medicine and creating a healthier, more equitable gaming industry. She is the founder of GamerDoc, the executive director of Queer Women of Esports, a faculty associate for the NYIT Center for Sports Medicine, and an editor for the Annals of Esports Research. She is a proud graduate of Wellesley College.

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About the Editors

Caitlin  McGee, PT, DPT, MS  received her undergraduate degree in neuroscience and exercise and sport science from Ursinus College and her doctorate in physical therapy from the University of Delaware. She has been working in esports and orthopedic medicine for 6 years. She is the co-owner and performance and esports medicine director of 1HP, a company that provides health and performance services to players, teams, and school esports programs, as well as a co-founder of the Esports Health and Performance Institute. Her areas of interest include the effects of exercise on player performance, player perceptions of pain, and the impact of mental health on pain and physical function in gamers. Melita N. Moore  is a quadruple board certified physician in physical medicine and rehabilitation, sports medicine, brain injury medicine, and lifestyle medicine at MedStar Health System in Washington, DC. She serves as a team physician in the NBA 2K League, WNBA, and NBA G League. She is one of a few team physicians of a professional esports team in the USA and is an international leader on health and wellness for gamers. In addition, she is a member of the board and chair of the Health and Wellness

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Commission for the Global Esports Federation. Her goal is to educate parents, gamers, and stakeholders on the importance of healthy lifestyles in a digital world.

List of Contributors

Kristen Beckman, MS, OTR/L  Upper Marlboro, MD, USA Carl  Daubert, MS Performance Coach Carl Consulting, Hanover Township, PA, USA Christopher  Ferguson, PhD  Department of Psychology, Stetson University, DeLand, FL, USA Rachel Kowert, PhD  TakeThis, Seattle, WA, USA Lauren  Trocchio, MSc, RD, CSSD, CSOWM, LD Nutrition Unlocked, LLC, Arlington, VA, USA

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What Is Esports? The Past, Present, and Future of Competitive Gaming Lindsey Migliore 1.1

Introduction

In 1958, hundreds of students lined up for an analog computer at the Brookhaven National Laboratory. Over the next three days, thousands would play the world’s first-ever game designed for entertainment purposes only, Tennis for Two. Since then, video games have exponentially evolved from their basement laboratory ancestral roots. Competitions, originally begun as a friendly split-screen match between friends or a quest for an arcade high score, have followed a similar growth trajectory. Competitive video gaming, known as esports, has exploded in popularity in recent years. With over 450 million viewers worldwide and almost $1 billion in revenue in 2020, esports is not a fad, but rather a technological and cultural phenomenon [1]. Esports Versus eSports

The stylization of esports has come under debate in recent years. In 2017, the Associated Press (AP) settled on “esports” over “eSports” or “e-sports.” Some organizations named prior to 2017 have chosen to retain their original stylization, but the authors recommend utilizing the AP stylization.

L. Migliore (*) GamerDoc, Washington, DC, USA e-mail: [email protected] © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 L. Migliore et al. (eds.), Handbook of Esports Medicine, https://doi.org/10.1007/978-3-030-73610-1_1

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To remain competitive in this popular and sometimes lucrative field, gamers often practice upwards of 12 hours a day, performing anywhere from 400–600 actions per minute. As such, they are susceptible to a unique set of injuries and disorders from these complex movements, extended screen time, and sedentary tendencies. This population needs motivated and educated healthcare providers familiar with their lifestyle and ailments to effectively prevent, diagnose, and treat relevant esports medical conditions. This chapter will impart the fundamental basics of esports necessary to understand the terminology and culture of competitive video gaming.

1.2

History

Almost 50 years prior to when over 100 million viewers tuned in for the League of Legends World Championships, the first esports tournament was held. 24 players competed in a Spacewar tournament at Stanford University on October 19, 1972. The 2019 champions were rewarded with $834,000 and a trophy designed by Louis Vuitton. The 1972 winners received an annual subscription to Rolling Stone magazine. The evolution of esports has always been closely tied to technological advancements. Before powerful computers were made affordable and lightning fast internet was seen as a right rather than a privilege, arcades and the eternal quest for a high score (Fig.  1.1) became the epicenter of early esports. A three-letter abbreviation, traditionally meant to display a player’s initials but used more creatively by some, displayed publicly and proudly for all other players to gaze upon, catalyzed the competition. In 1983, the United States National Video Game Team (USNVGT) was formed, laying the groundwork for esports organizations of modern day. In the 1990s, personal computers (PCs) and consoles became more reasonably priced, and subsequently more commonplace. The evolution of the internet allowed multiple computers to be simultaneously connected, enabling more complex multiplayer

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Fig. 1.1  Arcade high scores, depicted in brightly colored letters, served as the earliest origins of competitive gaming. Three-letter abbreviations typically signified a player’s initials, and corresponded to the highest point total in the game

engagements. In the mid-1990s, local area network (LAN) parties emerged. The concept of a LAN party is simple. Bring your own PC or console, connect them together, and compete for prizes ranging anywhere from bragging rights to large sums of cash [2]. As technology continued to mature, computers with greater processing power allowed for more advanced games to be developed. However, for the average person they still lacked general affordability. The Internet cafe served as a compromise. Gamers could rent time on PCs to engage in multiplayer games for a low hourly rate.

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While participation in gaming became more accessible, viewership still required physical attendance and subsequently lagged behind. This changed in the early 2010s with the availability of online streaming services, allowing tournaments to be broadcasted for anyone with an internet connection to view. In the late 2010s, esports became more mainstream as popular gaming titles formed competitive leagues and tournaments vastly expanded. With this expansion came a vibrant culture shift. In the public eye, the gamer was being seen less as a basement-dwelling sluggard and more as a talent, leading to the beginnings of acceptance of the “pro-gamer” as a viable career path. The education system served an integral role in organizing video game play. While high school and college gaming clubs have been in existence for decades, varsity esports teams at the collegiate level were relatively unheard of prior to the late 2010s. College organizations, with similar levels of institutional support as the traditional athletics teams, began competing in regional brackets. In 2018, Harrisburg University awarded full-ride scholarships to its entire esports roster, becoming the first institution to do so. Dedicated spaces for esports also began to flourish around the same time frame. In 2015, the Esports Arena opened in Santa Ana, California, and multiple indoor arenas dedicated to hosting esports events followed suit. In 2019, during the Eighth Olympic Summit, the International Olympic Committee announced it would consider sports-simulation games for an official Olympic event in the distant future. At the close of the 2010s, esports viewership in the United States had already eclipsed that of any other professional sport aside from football. Total tournament earnings for 2019 was a quarter of a billion dollars. The rich history of competitive video gaming is set to eclipse records and gain further popularity in the 2020s.

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Console Versus Computer Gaming

Game titles are played primarily on a personal computer or console. The mechanics of play differs drastically, depending on choice, and dictate injury susceptibilities. An understanding of the input devices is essential for any healthcare provider wishing to provide care to esports athletes.

1.3.1 Console Gaming A video game console is used to describe a computer designed primarily for game playing. Current popular brands include the Microsoft Xbox, Sony Playstation, and Nintendo Switch. Players employ hand-held controllers as the primary input device for movements and actions. The typical anatomy of a controller is shown in Fig.  1.2. While the design varies between brands, the dual analog stick has become the most popular configuration. Two analog sticks are arranged on opposite sides, each to be controlled by either thumb. The analog sticks function primarily in movement control (similar to a computer mouse), and have largely replaced the traditional gamepad. Specialized variants exist for specific games, such as steering wheels for driving games, or arcade sticks for fighting games. The controller also features buttons, triggers, or paddles on one or more sides. The physical mechanism by which players reach the buttons tends to vary based on preference and title being played, and will be discussed in depth in Chap. 5.

Claw Grip

“The claw” is an alternative grip used to reach the buttons on the front side of the control, while keeping the thumbs on the analog stick. The index finger is abducted and maximally flexed at the proximal and distal interphalangeal joint.

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Fig. 1.2  The anatomy of a controller. Directional buttons, also known as a “D-pad” are on the left side. Originally, but still occasionally used for movement until the popularity of the analog sticks, they often correspond to less-­ commonly used actions. Two pairs of triggers top the cranial section of the controller. Action buttons, either designated by shapes, letters or numbers frame the right side. Dual analog sticks, the hallmark of the modern design, sit either directly across from one another, or staggered, depending on the brand

1.3.2 Computer Gaming 1.3.2.1 Personal Computer (PC) Gaming, Mouse and Keyboard Gaming While a home computer is often utilized for casual PC gaming, more serious competitors have specialized “builds” with exponentially more robust computing power. The input devices are most commonly a computer keyboard and mouse. Specialized gaming mice are available with lightweight designs and additional buttons on the sides. The mouse is generally held with three different grips, and the specific ergonomics of each are discussed in detail in Chap. 5.

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1. Palm: The palm is in contact with the proximal mouse, and fingerpads are in full contact with the distal mouse. 2. Claw: Metacarpophalangeal flexion coupled with wrist extension places less of the palm in contact with the mouse, and only the distal phalanges. This allows for more precise movements. 3. Tip: The palm is completely lifted from the mouse, with only the distal tips of the fingers being used to control movement. The keyboard can be used in a variety of fashions. For games involving avatar control, the classic “WASD” keyboard is used for movement with the left hand, with the ring finger on A (move left), middle switching between S (move back) and W (move forward), and index on D (move right). Thus, the term “W Key” denotes an aggressive, forward dominated play style as a player’s finger does not leave the “move forward” button. When gaming, keyboards are frequently angled differently from a traditional horizontal position, as shown in Fig. 1.3. This practice was started in Internet cafes, where narrow desks limited the range of mouse movement. In lieu of sacrificing accuracy, keyboards are turned completely vertical, allowing for wider mouse territory. Vertical keyboards are still in usage outside of Internet cafes for reasons ranging from personal preference, ease of handling, and faster actions.

1.4

Esports Genres

The breadth of video game titles available for play rivals that of any other form of entertainment. While competitive play exists for everything from casual mobile games to farming simulators, titles are often separated by “tiers.” Originally developed by Jen Hilgers, games are placed into one of three tiers based on prize pool amounts, hours watched, and social media impact. While the topic is in itself largely controversial due to personal opinions and debates on method of calculation, the following genres are generally considered tier-level esports [3].

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a

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Fig. 1.3  Horizontal versus vertical keyboard orientations. (a) The traditional horizontal orientation employed by non-gamers and the casual gaming population. The player’s left hand rests on the keyboard, typically on the WASD keys for first- and third-person games, and the right hand utilizes the mouse for aiming and targeting purposes. (b) The vertical orientation involves turning the keyboard somewhere between 0 to 90°, freeing up more space for mouse movement

1.4.1 First-Person Shooter 1.4.1.1 Call of Duty, Overwatch, Counter-Strike: Global Offensive, Halo, Rainbow 6 Siege First-person shooter (FPS) is a genre centered around weapons-­ based combat through the eyes of the game’s character (first-­ person view). This is in contrast to third-person games, where players can see the body of the character they control. Across titles, similar game modes are utilized. The most traditional game mode is “Deathmatch”, where points are awarded for enemy eliminations. The “Kill to Death”, or “K:D” ratio is the

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amount of enemy kills versus the times a player themselves died, with a higher number signifying greater success. Other popular game modes include video game versions of capture the flag and queen of the hill, where players must hold onto a landmark for a period of time, with that landmark often switching after a set period. Respawning, that is, returning to life after being eliminated by the opposing team is common. Players generally respawn in areas near where their teammates are located.

Spawn Camping

Spawn camping is the practice of positioning oneself in direct sight of the opposing team’s spawn location, with the goal of immediately eliminating them upon respawning, and subsequently having no chance of defense. FPS games are typically one of the most popular genres in the casual gaming population. Although there is limited data on esports, evidence suggests that playing FPS games promoted greater cognitive flexibility, as demonstrated by greater performance on a task-switching paradigm [4].

1.4.2 Battle Royale 1.4.2.1 PlayerUnknown’s Battlegrounds (PUBG), Fortnite, Apex Legends, H1Z1, Call of Duty: Warzone The Battle Royale genre (BR) blends classic elements of survivalism with last-person standing. Either first- or third-person point of views are applied. The overarching goal is to scavenge for supplies while avoiding being eliminated by enemies. Games often employ the same mechanics, with players randomly spawned or dropped onto a map from an aircraft. The maps are often identical game-to-game, with weapons, equipment, and consumables varying locations each time based on a random number generator (RNG). Players will have no or only basic weapons in the beginning, and may acquire and upgrade their items during the course

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of the match. As enemies are eliminated, the “safe area” of the map shrinks, d­ rawing survivors towards the center. Once eliminated, players often do not respawn and must start another match. The winner is the last player or team alive [5]. Origin Story

One of the original BR games, PlayerUnknown’s Battlegrounds, was based on the 2000 Japanese film “Battle Royale”.

1.4.3 Real-Time Strategy 1.4.3.1 Starcraft, Warcraft Strategy video games are often based on planning and tactical decision making to achieve victory. The category is subdivided based on whether play proceeds in a turn-based or real-time fashion. Real-time strategy (RTS) games are by far the most popular in esports. In typical RTS titles, players are given a bird’s eye view of the map, over which resources are splayed. The player operates in a god-like capacity, often controlling multiple avatars at once. Victory is achieved by completing certain objectives while utilizing common themes: resource management, base construction, and technological advancement. Resources can be gathered from the environment, which are used to create units and structures. There is often a technological side to the game as well, with more advanced upgrades conveying a tactical advantage. Both micro- and macromanagement skills are needed. Each individual unit constantly requires specific instruction, yet the overall objective must be simultaneously worked towards, often to build a large and more skillful army than the opponent. This subgenre is most commonly played on PC, with the mouse used to navigate the map and select units or targets. The “Click and Drag” technique is applied by clicking a space and dragging the mouse over multiple units. Keyboard buttons coincide with different commands, and actions per minute (APMs) in RTS games can exceed 600.

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1.4.4 Multiplayer Online Battle Arena 1.4.4.1 Defense of the Ancients (Dota), League of Legends (LoL), Smite Originally classified as a subgenre of strategy games known as “action real-time strategy” (ARTS), multiplayer online battle arena (MOBA) titles have earned their own category. As opposed to directing multiple units and avatars at once, the integral difference between RTS and MOBA is that only one main avatar is controlled, often called “heroes.” Furthermore, players may work cooperatively with other teammates, usually in squads of five, towards common objectives. Non-player characters (NPCs) spawn on the map, offering each player an advantage or additional obstacle. Maps often utilize isometric graphics, a viewpoint that is a cross between top-down and side view, effectively producing a three-dimensional effect and allowing the environment to be visualized from an entirely different angle than other genres. Victory is often achieved either via eliminating every member of the opposing team, or by destroying the enemy’s main structure. These structures are reached by progressing down predetermined paths in the map, often called lanes. Throughout these lanes are other structures that may spawn NPCs or deal damage, which can be captured and controlled. Players may also be designated by which lane they attack down, as a “Top Lane” “Mid Lane” or “Bottom Lane.” Team Composition

Heroes have varying abilities and skills that are designed to complement other team members. The common classes are “tank,” “healer,” and “damage-per-second,” Tank classes are designed to draw the enemies’ attention while taking large amounts of damage. Healer, or other support classes, keep teammates alive and may offer other unique support skills. Damage-per-second (DPS) characters are designed to reign damage. Overwatch, a popular FPS title, relies heavily on team composition.

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1.4.5 Fighting 1.4.5.1 Street Fighter (SFV), Tekken, Mortal Kombat, Dragon Ball FighterZ, Injustice, Skullgirls Player-controlled characters battle each other in a fixed-space, close-quarters environment. Traditionally, all players share the same sideways, 2D viewpoint. The primary objective is to deplete your opponent’s health bar to zero over multiple rounds (typically a best of three format). Players can choose from a multitude of characters, each with their own distinct attacks, counterattacks, and blocks. Each character has their own set of moves, with more complex combinations corresponding to more powerful attacks (special attacks). Unlike FPS, RTS, and MOBA genres, fighting games are more commonly played on consoles with portable arcade sticks or controllers. While traditional titles like Tekken and Mortal Combat are one-versus-one, Super Smash Bro allows for more than two characters to battle at one time. FGC

The fighting game community is often abbreviated as FGC.

1.4.6 Digital Collectible Card Game 1.4.6.1 Hearthstone The popularity of digital collectible card games (DCCGs) was heralded by that of collectible card games like Magic the Gathering and Pokemon, and borrow the same mechanics. They can also be classified as turn-based strategy games. Players manage a personalized collection of cards that they do battle against an opponent with, typically in a one-versus-one format. Cards may signify the introduction of a character, a spell, or power up. The goal is to use the deck to reduce an opponent’s health to zero. More powerful cards can be obtained via gameplay, which are in turn used to build more powerful decks.

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1.4.7 Sports Simulation 1.4.7.1 NBA2K, NHL, Rocket League, FIFA Simulation games are intended to closely copy real-world activities, most commonly a sport. Sports simulation games are often named after the traditional athletics organization they emulate. Unlike other genres, where years or decades may go by before a new title is released, updated sports simulation games are often released annually. Players control characters that usually represent real athletes, with statistics modeled after their actual height, weight, and skill sets. The notable exception to these concepts is Rocket League, which has been appropriately described as “flying car soccer.” Players guide cars inside of a giant arena with the overall goal of knocking a giant ball into your opponent’s net.

1.5

Competitions

Organized esports play can take a variety of forms, with leagues and tournaments among the most common. In league play, professional teams field elite lineups to compete against other professional teams throughout a season. Teams may be promoted or relegated to lower leagues, depending on their performance throughout the year. More recently, competitive dynamics have shifted towards the traditional sports franchise model as esports finds more mainstream success and higher viewership. By removing the relegation and promotion dynamics, teams operate on a more permanent and thus more reliable basis. This fosters stable fan bases, and larger and more consistent investments. In 2017, Riot Games and Blizzard Entertainment began operations of the North American League of Legends Championship Series and the Overwatch League (OWL). The OWL was formed from 12 international teams. These teams competed throughout a season, each vying for a finite number of playoff spots. Playoffs culminated in a championship match which crowned one team

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supreme. Since then, the NBA2K League (basketball), eMLS (soccer), and Call of Duty League have all followed suit. Franchise teams often pay their players a salary, rather than relying on prize money for compensation [6]. Tournaments continue to remain popular in non-team-based titles. Individuals or squads participate in qualifiers, which may be open to the public or by invitation only. This initial stage may be remote, with matches played online. While this favors the nonprofessional player who may not have the time or resources to engage in competitive gameplay outside of their home, it allows for an element of cheating or hacking as there are obviously no referees present. Once qualified, most tournaments involve physical travel and competition on a group stage. Local area network (LAN) tournaments were arguably the birthplace of esports, and are still popular amongst amateur video gamers. Tournaments are held in venues ranging from basements to convention centers. The tournament model favors amateur players, as they do not have to be drafted or recruited to a specific team to compete. Prize money for tournaments can range from meager to millions of dollars. In July 2019, the Fortnite World Cup awarded $30 million in prize money in a single weekend.

1.6

Video Game Live Streaming

While competition is what inherently defines esports, video game live streaming, known simply as “streaming” for short, offers an alternative way to earn income. Gameplay is broadcasted live, though websites such as Twitch, Mixer (Microsoft’s streaming service that shutdown in 2020), YouTube Gaming, and Facebook Gaming. Popular streamers such as Ninja and Shroud often broadcast for up to 100,000 viewers at one time, and can earn incomes that exceed several million dollars a year [7]. With streaming, entertainment rather than competition is rewarded. Subsequently, this favors more unique and captivating personalities rather than the best and most talented player.

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Conclusion

Esports earnings in 2021 are expected to exceed one billion for the very first time, marking a gigantic milestone. If viewership trends continue at the current trajectory, these numbers will only continue to grow. Despite the explosion of esports participants, leagues, tournaments, and sponsors, stigma and naivety still impedes the professional gamer from being seen as any other person whose success and career depends on the performance of their body and mind: an athlete. Remaining competitive in this field requires the same amount of physical and mental training and commitment as any other form of professional athletics. Instead of running sprints and lifting weights, esports athletes are cementing complex motor patterns involving miniscule muscles of the hand and perfecting their hand eye coordination. In lieu of a gym, gamers prepare in a cooled and darkened room, often lit only by the glow of a computer monitor and LED lights of a specialized gaming PC. Gamers are susceptible to their own unique set of injuries and illness that necessitates the attention of healthcare providers knowledgeable of their lifestyles, training schedules, and play mechanics.

References 1. Newzoo. Global esports market report. 2019. https://resources.newzoo. com/hubfs/2019_Free_Global_Esports_Market_Report.pdf?utm_ campaign=Esports%20Market%20Report. Accessed 7 Jan 2020. 2. Kent S. The ultimate history of video games. New York: Random House International; 2002. 3. Hilgers J. Esports games tiers. 2017. https://esportsobserver.com/esports-­ games-­tiers. Accessed 7 Jan 2020. 4. Colzato LS, van Leeuwen PJ, van den Wildenberg WP, Hommel B.  DOOM’d to switch: superior cognitive flexibility in players of first person shooter games. Front Psychol. 2010;1:8. https://doi.org/10.3389/ fpsyg.2010.00008. 5. Fillari A. Battle royale games explained: Fortnite, PUBG, and what could be the next big hit. 2019. https://www.gamespot.com/articles/battle-­

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royale-­games-­explained-­fortnite-­pubg-­and-­wh/1100-­6459225/. Accessed 7 Jan 2020. 6. Seiner J. What’s overwatch? Why is it on ESPN? 8 things to know about competitive gaming. 2018. https://www.chicagotribune.com/sports/ breaking/ct-­spt-­overwatch-­league-­esports-­espn-­20180726-­story.html. Accessed 7 Jan 2020. 7. Chaloner P, Sillis B. This is esports (and how to spell it). London: Bloomsbury Sport; 2020.

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Upper Extremity Disorders in Esports Lindsey Migliore and Kristen Beckman

2.1

General

Arguably, the most important and essential parts of a gamer’s body are their hands. Observational data has found that actions per minute for games like Starcraft II can reach upwards of 300– 600. That breaks down to 10 actions per second. With a total of 34 individual muscles coordinating those delicate movements, a multitude of issues can arise. Injuries to the upper extremity in the esports population most likely result from chronic microtraumas rather than acute processes. As a result, symptoms may be insidious, and worsen slowly, often below the threshold of a player’s consciousness. Furthermore, because of the high level of importance placed on the upper extremity, exploration of how the symptoms have affected the player’s functionality is critically important. What are they prevented from doing because of the symptoms? If the answer is nothing, then focus should be placed on prevention and

L. Migliore (*) GamerDoc, Washington, DC, USA e-mail: [email protected] K. Beckman Upper Marlboro, MD, USA © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 L. Migliore et al. (eds.), Handbook of Esports Medicine, https://doi.org/10.1007/978-3-030-73610-1_2

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rehabilitation. If players have begun to adjust their play style or lifestyle as a result, such as switching keybinds due to discomfort or weakness, then more aggressive treatment is warranted. As with any field of medicine, an understanding of the primary goals of care are essential to effective practice.

2.1.1 Anatomy The upper extremity includes structures from the shoulder to the tips of the fingers. Historically, “arm” refers to the region from the shoulder to the elbow, whereas “forearm” refers to the region from the elbow to the wrist. The majority of pathology in the esports population occurs more distally in the forearm. Subsequently, proximal structures will be touched on only briefly. The upper extremity consists of a total of 64 bones, with 10 in the shoulder and arm, 16  in the wrist, and 38  in the hand. The humerus of the arm articulates with the radius and ulna at the elbow joint. The medial and lateral epicondyles of the humerus are prominent anatomical structures that serve as attachment points for muscles of the distal arm. The medial epicondyle is more prominent than its lateral component and serves as a major attachment point for flexors and pronators of the forearm. It also protects the ulnar nerve with a groove along the posterior side. The lateral epicondyle serves as an attachment point for extensors and supinators. The radius and ulna are connected by a fibrous interosseous membrane. Distally, they articulate with respective carpal bones of the hand. At the wrist, the extensor tendons are separated by six anatomical tunnels called compartments, which are shown in Fig. 2.1 and described in Table 2.1. The brachial plexus provides the majority of nerve supply to the upper extremity and arises from the anterior rami of the lower four cervical nerves and first thoracic nerve. The plexus forms the major nerves of the upper extremity: the ulnar, median, and radial nerve.

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Fig. 2.1  The extensor compartments of the wrist cover the dorsal surface of the radius and ulna, and contain tendons of wrist, finger, and thumb extension, as well as thumb abduction Table 2.1  The extensor compartments of the wrist components and actions Compartment Components 1 Abductor pollicis longus Extensor pollicis brevis 2 3 4 5 6

Extensor carpi radialis longus and brevis Extensor pollicis longus Extensor digitorum Extensor indicis Extensor digiti minimi Extensor carpi ulnaris

Actions Thumb abduction Metacarpophalangeal extension Wrist extension Thumb interphalangeal joint extension Finger extension 5th digit extension Wrist extension and adduction

2.1.2 Evaluation A challenge that many practitioners in the realm of esports medicine may face is the relative unwillingness or uneasiness to address illnesses affecting the upper extremity. Some degree of discomfort or pain may be considered normal for many who have

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placed their bodies under such specific stresses for an extended period of time. Thorough knowledge of not only anatomy and pathology but also specific gaming mechanics relevant to the player is essential to proper diagnosis. Furthermore, when pathology is found, examination of the contralateral side is paramount for tests from simple range of motion to electrodiagnostics. This can help eliminate false positive test results and avoid unnecessary interventions.

2.1.2.1 History Taking Careful history taking is an essential first step, and can often narrow the diagnosis drastically with only a few basic questions. Certain clinical pearls are especially helpful for the esports athlete, and are discussed below. Location Where exactly symptoms arise can reveal vast amounts of clinical information. It can be helpful to ask them to use one finger to localize the area, rather than their entire hand. Although not a hard-and-fast rule, ligament and tendon injuries tend to be more easy to localize in that fashion than nerve injuries, which can present more diffusely. Onset What was the player doing at the time of injury? A slow, insidious course may have a difficult onset to pinpoint. This may suggest chronic microtraumas or compression as causative factors. An acute onset of symptoms is less common in this patient population. Due to the repetitive strain of gaming, underlying pathological changes may make structures more susceptible to acute injuries. Therefore, acute injuries may be more complicated than originally assumed. Did the symptoms start with any recent changes in setup, such as a new keyboard or controller? Different keyboard angles and sizes, the addition of paddles, or mouse heights may provoke specific ailments.

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Palliation and Provocation What activities bring on the symptoms? For some, this will most likely be extended gaming sessions. Do specific titles make symptoms worse than others? For example, in more straightforward first-person shooter titles with traditional WASD keybinds, the breadth of finger range of motion is much smaller when compared to games with build mechanics or complicated keybinds. Furthermore, pain that is worse upon awakening may point towards nerve injuries that are aggravated by immobility in positions assumed while sleeping. Quality Although not a hard-and-fast rule, pain that is described as “burning,” “electric,” and “radiating” may more commonly be associated with nerve injuries whereas words like “sore” and “stabbing” may describe tendon or muscle involvement. Radiation Do the symptoms travel? If so, where? Symptoms that travel across two joint lines may point more closely to nerve injuries rather than tendon or muscle involvement. The symptoms may also follow a specific dermatomal or peripheral nerve pattern, further aiding diagnosis. However, nerve injuries may also be the hardest to pinpoint, and patients may gesture with their entire hand over a specific area, rather than being able to label the exact spot as with conditions like epicondylitis. Esports History A careful esports history is also essential, and should include what system the athletes primarily utilizes, what main titles they are playing, training schedule details, and what forms of physical activity are being utilized. As mentioned before, video games drastically differ in mechanics, and may result in a variety of injury patterns. If possible, a thorough evaluation of the exact keybinds a player is using may reveal an overuse of the affected area. This

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will also provide valuable insight into possible interventions once a diagnosis is made.

2.1.2.2 Physical Examination A focused physical examination should include a careful inspection of the involved area, as well as the joints above and below. For a musculoskeletal examination to be complete, it must include inspection, range of motion (both passive and active), palpation, muscle strength testing, and further special testing. Inspection Subtle clues and diagnostic details can be glimmered from simple inspection. The area should be completely exposed to allow for thorough evaluation. Inspection can reveal things such as swelling, erythema, and deformity. Palpation When palpating a possible area of pain, care should be taken to avoid the area of maximal tenderness until the last possible moment. This will increase the chances of a successful exam. Palpation allows examiners to also feel for areas of tautness, warmth, and effusions. Range of Motion Both passive and active range of motion is essential to determining not only pathology, but possible therapeutic interventions. For example, severely restricted wrist flexion due to muscle tightness might not be the presenting symptom, but treatments that focus on improved range of motion may help the underlying diagnosis. Range of motion testing should also include pinpointing the causative motion, if one exists. A small amount of resistance may be applied to aid diagnosis. Sensory Examination A basic understanding of peripheral nerve distribution (Fig. 2.2), as well as dermatomes, is essential to effective physical examination. Of importance, there exists a great deal of sensory ­redundancy

Dorsal View

Posterior antebrachial cutaneous nerve

Ulnar nerve

Ulnar nerve

Fig. 2.2  Cutaneous innervation of the hand via peripheral nerves

Radial nerve

Median nerve

Ventral View

Median nerve Palmar Branch

Radial nerve

Median nerve

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in the upper extremity. This overlapping of nerve distributions can often confound the examination. Motor Examination Manual muscle testing can be performed to establish strength and also reveal areas of imbalance. It is important to realize that in gamers hand dominance might mean less in terms of side-to-side differences. For example, in the normal population, the dominant hand may have a relative strength in finger abduction. However, for a right-handed PC gamer who utilizes the “Tab,” “Caps Lock,” and “Shift” keys more frequently (Fig. 2.3), the left side may in fact be stronger. This could be an important differentiator between a clinical suggestion of cubital tunnel syndrome and a simple keybind explanation. Another important point is that pain in a specific tendon or joints can result in give-way weakness, and should be appropriately documented [1]. Tinel’s Test The Tinel’s test is a technique used to detect nerve inflammation, and can be applied to multiple anatomical locations. To perform, light percussion is applied to a nerve. The test is considered positive if paresthesia is elicited in the nerve’s distribution.

Fig. 2.3  Aerial keyboard view with buttons most commonly accessed using the fifth digit. These keys are often bound to frequently used actions such as crouch, inventory, map, sprint, or special attacks. The fifth digit is persistently utilized for these actions as the second to fourth digits are usually engaged in movement, thus leaving only the first and fifth digits readily available

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2.1.2.3 Imaging Ultrasonography Musculoskeletal ultrasound (US) can be one of the most useful imaging techniques when approached correctly in the hands of a skilled clinician, so much so that it can be considered an extension of the physical examination. Examiners trained correctly can not only obtain real-time, dynamic images of involved structures, but offer more precise interventions. Other advantages include absence of radiation exposure, ease of accessibility, patient involvement, and cost-effectiveness. A variety of transducers, also known as probes, are available. The most commonly used probes for the evaluation of the upper extremity are the linear and small-footprint linear array. Linear probes are more commonly used for superficial anatomy such as the tendons and nerves of the hand and wrist. The small-footprint linear array probe, also known as the hockey-stick transducer for its characteristic appearance has a higher frequency, and can provide a higher image resolution for the most superficial of structures. A basic understanding of US terminology is essential for every clinician who wishes to understand and effectively treat esports conditions.  The fundamentals of US comes from a structure’s echogenicity, that is, how strongly a structure reflects the transducer’s sound wave. A hyperechoic structure (with high echogenicity) will strongly reflect the sound of the ultrasound back at the transducer. This increased signal will result in the structure appearing bright on US. Hyperechoic structures include tendons and the outer surfaces of bone. On the contrary, a hypoechoic structure will appear darker, and denotes a lower density. Anechoic structures will appear black and do not reflect any sound waves. Fluid is the most relevant anechoic substance. In reality, most structures are a mixture of echogenicity based on their underlying heterogeneity. For example, a peripheral nerve consists of hypoechoic individual nerve fascicles surrounded by hyperechoic epineurium.

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A thorough examination includes evaluation of the structure in both short axis and long axis. This allows for not only correct identification of structures, but more complete analysis for pathology. In the long axis, a nerve may appear similar to surrounding tendons, but on short axis, the characteristic “honey-comb” appearance is difficult to confuse. Practitioners who wish to learn more about ultrasonography as a diagnostic tool are encouraged to refer to dedicated handbooks [2]. Radiography X-ray has limited value in a variety of these cases, aside from ruling out a more insidious cause. If the history lacks a traumatic event, x-ray is rarely indicated. Magnetic Resonance Imaging While Magnetic Resonance Imaging (MRI) has the advantage of lack of radiation exposure and thorough evaluation of soft tissue structures, it can be costly and oftentimes unnecessary. However, when the diagnosis is uncertain after thorough physical examination and ultrasound, MRI may be necessary. T1-weighted images provide the best resolution for examining anatomy, whereas T2-weighted images can demonstrate the presence of fluid or cysts [3]. Clinical Pearl

When Triangular Fibrocartilage Complex  involvement is suspected, MRI is an essential diagnostic tool. Electrodiagnostics In a trained hand, electrodiagnostics (EDX) can provide vital information concerning possible neuromuscular disorders. They are best considered extensions of a thorough neurological examination, rather than separate tests on their own. Given the intense technicality and choice of study parameters based on individualized clinical decision making, diagnostics should be approached only after a thorough differential diagnosis has been formed.

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These studies can include a multitude of techniques, but for the scope of this textbook we will discuss nerve conduction studies (NCS) and needle electromyography (EMG). NCSs are performed by placing recording surface electrodes over the motor or sensory innervation of a specific nerve. The corresponding peripheral nerve is then stimulated proximally, and the motor and sensory responses are recorded. The responses are known as compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs), respectively. Furthermore, the speed of impulse transmission can also be quantified as "conduction velocity". These values can then be compared to standardized numbers to evaluate for neuropathic and myopathic lesions, as well as disorders of the neuromuscular junction. When abnormal values are found, contralateral investigation is strongly recommended to rule out congenital or anomalous abnormalities [4]. EMG utilizes a needle electrode placed directly within the muscle, allowing for individual motor unit examination. It is often more challenging and places the patient in a higher level of discomfort than NCS. Any provider who refers a patient for an EDX should warn their patient at that time that the test involves needle examination of the involved area and may cause them discomfort [5]. EDX can be helpful in pinpointing disorders of the peripheral nervous system, which are all too common in the gaming population. Poor ergonomics, hypertonicity, and prolonged compression is an environment ripe for nerve compression and damage.

2.1.3 Treatment 2.1.3.1 Therapeutic Modalities The most common modality utilized by patients prior to presentation is by far cold therapy. Cold therapy can reduce pain via vasoconstriction, decreased inflammation and metabolic demand [6]. Nontraditional modalities, such as acupuncture, yoga, and osteopathic manual therapy, may also be helpful for certain cases. Kinesio tape is an elastic therapeutic skin tape thought to act by providing support to muscles and joints, thus allowing for continued movements with decreased pain. Current evidence is mixed

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for the role of kinesiotaping, but it may be beneficial for certain conditions [7, 8].

2.1.3.2 Rehabilitation Referral to an occupational therapist or certified hand therapist can allow patients to take a more active role in their recovery. When weakness is present on physical examination, this referral becomes more than necessary. Even with the most motivated of populations, self-directed programs may not be as regular or effective as a formal course of therapy. 2.1.3.3 Pharmacology Over-the-counter medications such as nonsteroidal anti-­ inflammatory drugs (NSAIDs) and acetaminophen may provide temporary pain relief in acute phases. NSAIDs such as ibuprofen and naproxen block the inflammatory cascade via inhibiting the activity of cyclooxygenase enzymes (COX 1 and/or 2). Long-­ term NSAID usage can have deleterious effects, such as gastrointestinal distress/damage and kidney dysfunction. NSAIDs may also interact with other medication metabolism. Topical NSAIDs can provide pain relief for some of the more superficial structures while circumventing the deleterious adverse effects. Anticonvulsants and antidepressants have been proven effective for certain painful conditions. Neuropathic causes, such as peripheral nerve entrapments, with symptoms of paresthesia and dysesthesia may respond to such agents. It is important to educate patients that these medications will have little effect on numbness [9]. 2.1.3.4 Interventions For cases unresponsive to conservative management, further intervention may be necessary. Nerve blocks, regenerative medicine injections, and corticosteroid injections should always be performed under ultrasound guidance for greater efficacy and avoidance of adverse effects. Steroid injections are not recommended for long-term use due to the deleterious effects on healthy cartilage, bones, and tendons.

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Hand and Wrist

2.2.1 Radial Styloid Tenosynovitis De Quervain’s Tenosynovitis, Gamer’s Thumb, Selfie Thumb, Falcon Thumb, Mommy’s Thumb

2.2.1.1 Overview With the advent of the smartphone, this clinical syndrome previously associated with new parents has risen to prominence in the public eye. Radial styloid tenosynovitis is characterized by pain in the radial wrist, specifically during thumb or wrist movement. 2.2.1.2 Pathogenesis The first compartment of the wrist is composed of the extensor pollicis brevis (EPB) and abductor pollicis longus (APL). Combined, their actions work to bring the thumb away from the palm in abduction and extension. Clinical Pearl

A useful mnemonic for remembering the involved tendons in this condition is “All Peanut Lovers Eat Peanut Butter”. Both the APL and EPB lie in a fibrous sheath within the synovial lining. This sheath crosses the radial styloid and passes under the extensor retinaculum. Cadaverous examination has revealed that there may be a small septa separating the two, or they may have entirely different synovial sheaths. The presence of a septum is thought to increase the risk of developing radial styloid tenosynovitis, and may have clinical treatment implications which will be discussed later [10]. Repetitive trauma such as chronic overuse or rapid increase in usage places shear forces on the tendons resulting in thickening and tenosynovitis. Positions that increase the stress on the tendons, such as extension and abduction, are thought to lead to an increased risk of injury.

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Despite being described as a stenosing tenosynovitis, which describes an inflammation of the synovial sheath of a tendon, this description is not entirely accurate. Histopathological evaluation of patients who were treated surgically for radial styloid tenosynovitis have shown the process is noninflammatory in ­ nature and instead a degenerative process [11].

2.2.1.3 Presentation Nonspecific pain in the radial wrist is a common presenting symptom. Pain may radiate into the thumb or down the forearm, and can be described as sharp or burning. Symptoms are often aggravated by thumb or wrist movement, including rotatory and gripping movements, and when using a controller’s analog stick. With advanced disease, patients may complain of weakness with grip. With most overuse injuries, the onset is often gradual with no clear defined onslaught. 2.2.1.4 Diagnosis This is largely a clinical diagnosis with no advanced imaging required for uncomplicated cases. Although there are  no high-­ quality clinical studies on the subject, the authors speculate this is more common in controller players than PC, given bilateral thumb positioning. Physical Examination Inspection may reveal mild swelling overlying the radial styloid or just proximal, and palpation of the area may elicit pain. Precise location is helpful when determining if the patient’s lateral wrist pain is due to radial styloid tenosynovitis or intersection syndrome. Clinical Pearl

Symptoms from radial styloid tenosynovitis is more commonly distal and lateral, whereas intersection syndrome presents more dorsal and proximal.

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a

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b

Fig. 2.4  Finkelstein’s test. (a) Patients place their thumb inside of a closed fist. (b) The examiner then stabilizes the forearm with one hand, and ulnarly deviates the patient’s hand with the other. The arrow corresponds to the most common area of pain, and signifies a positive test

Finkelstein’s Test

This test can often be diagnostic if performed correctly. As shown in Fig.  2.4, patients are instructed to grasp their thumb in their palm, and close their fist. The examiner then stabilizes the forearm with one hand, and ulnarly deviates the patient’s hand with the other. Reproduction of pain over the EPB and APL signifies a positive test, and is usually diagnostic of radial styloid tenosynovitis. As many gamers and non-gamers may have never stretched these muscles before, tightness should be expected and may not correlate with injury. Imaging Imaging is usually not necessary, but ultrasound can confirm the diagnosis if the differential is still broad. Ultrasonographic evaluation can reveal thickening of the suspected tendons. A thin echogenic line between the APL and EPB tendons signifies the presence of a septum, which may predispose a patient to tenosynovitis [12].

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2.2.1.5 Treatment Therapeutic Modalities Historically, treatment of this condition was accompanied by immobilization of the thumb in a thumb spica splint. Of note, splints must immobilize the thumb MCP joint in order to effectively off-load the tendons in question. However, as the condition is not inflammatory in nature, thumb splinting may only provide temporary pain relief, and not address the underlying pathological process. Activity modification, such as utilization of a shorter analog stick, can decrease thumb extension and abduction and subsequently decrease stress on the involved tendons. For PC games, a knowledge of a patient’s keybinds on the affected side can often aid in prevention. After pain has subsided, a comprehensive therapy program that involves strengthening exercises, with a special focus on eccentrics and progressive tendon loading, can help adopt a more conducive tendon architecture. The mainstay of treatment is a combination of thumb spica splint wearing schedules coupled with targeted exercises. Further, kinesiotape can help further stabilize and decompress the joint while performing aggravating activities. Common concentric and eccentric strengthening exercises include wrist extension/flexion, radial/ulnar deviation, thumb isometric holds, as well as thumb and pinch variations. Exercises can be done with or without weight and should not be done in excess or to the point where pain is felt. Pharmacological Management Oral NSAIDs may provide temporary, symptomatic relief but should be avoided for long-term treatment. Interventional Medicine For cases not controlled with oral medications and rehabilitation, further interventions may be necessary. Corticosteroid injection can be effective for around 50% of patients, and should always be

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done under ultrasound guidance. If a septum or separate synovial sheaths are found, multiple sites may need to be injected in order to provide effective treatment [13]. Surgical release may be the final option for the most advanced cases. The first dorsal compartment sheath is opened longitudinally, thus completely releasing the tendons. While this has been shown to be effective, damage to the radial sensory nerve can result [14].

2.2.2 Intersection Syndrome Proximal Intersection Syndrome, Crossover Syndrome

2.2.2.1 Overview Often initially misdiagnosed as radial styloid tenosynovitis, intersection syndrome is caused by aggravation of the first and second dorsal muscle compartments at their intersection point. 2.2.2.2 Pathogenesis The first dorsal compartment of the wrist containing the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB) crosses over the muscle bellies of the second compartment of the wrist containing the extensor carpi radialis longus (ECRL) and brevis (ECRB) tendons. This occurs approximately 4 cm p­ roximal to Lister’s tubercle. The ECRL and ECRB largely function in wrist extension, whereas the APL and EPB are responsible for thumb abduction and extension. With repetitive wrist extension, friction can develop between the two compartments at their crossing point and stimulate an inflammatory response. With continued aggravation, tenosynovitis can develop in one or both compartments. This is more commonly seen when the hand is held in a gripped position and then subjected to flexion and extension, but can occur in a multitude of cases such as PC players with distant thumb keybinds or console players [15].

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2.2.2.3 Presentation The presenting symptom is often dorsal wrist and distal forearm pain overlying the area of intersection, which is proximal and dorsal to the radial styloid. Patients may also describe a sensation or sound of “squeaking” during movements that elicit pain. This sound is unique to intersection syndrome, and its presence should place this diagnosis at the top of the differential. 2.2.2.4 Diagnosis Intersection syndrome is primarily a clinical diagnosis. The largest diagnostic hurdle is often differentiating it from radial styloid tenosynovitis. Physical Examination Palpation may elicit tenderness over the site of intersection, and a small amount of swelling may be visible. Active range of motion testing may reveal crepitus when performing the respective muscle actions, which are wrist and thumb extension. Of note, the presence of crepitus should move intersection syndrome to the top of the differential diagnosis. Resisted extension and supination may reproduce pain in the same distribution. Imaging If further diagnostics are needed aside from history and physical examination, bedside ultrasound should be the first step. The most common finding is peritendinous edema. Instead of the usual hyperechoic plane separating the tendons, a hypoechoic area of tendon sheath fluid may be present, signifying underlying tenosynovitis. If the process is chronic, tendon thickening may also be present [16].

2.2.2.5 Treatment A temporary period of rest and recovery, conservative management focusing on activity modification, and therapeutic exercises are usually sufficient for treatment. However, for recalcitrant cases, further intervention may be necessary. Once the diagnosis of intersection syndrome is made, the laterality offers further insight. With console controls, the wrist is usually relatively stable, so thumb movement may be a less common

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cause. If a patient’s keyboard hand is affected, careful examination of the height and wrist angle while gaming should be noted and adjusted appropriately. The ergonomics of gaming will be discussed in detail in Chap. 5. Therapeutic Modalities Given the superficial nature of the structures, ice may provide temporary pain relief as well as aid in reducing swelling. There are not currently well-established guidelines for rehabilitation of this condition, but referral to a hand therapist should be considered for all patients who do not respond to above treatments. Supervised wrist and thumb strengthening exercises, along with tendon glides and stretches can aid in both prevention and ­recovery. Pharmacological Management Oral anti-inflammatories may provide temporary pain relief and should be avoided in the long term. Topical anti-inflammatories may also be of use, given the superficial structures and inflammatory nature of the disorder. Interventional Medicine When conservative management fails, corticosteroid injections under ultrasound guidance can be a logical next step. In rare cases, surgical debridement and release involving the release of the second dorsal compartment can provide relief [17]. Intersection Syndrome Versus Radial Styloid Tenosynovitis

Both involve the first compartment of the wrist, but intersection syndrome occurs more proximally, where the first compartment crosses over the second. Subsequently, pain from intersection syndrome will be more dorsal, and radial styloid tenosynovitis pain more radial, as shown in Fig. 2.5. Crepitus has only been reported in intersection syndrome, and is historically absent in radial styloid tenosynovitis.

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Fig. 2.5  Common locations for pain for (a) intersection syndrome and (b) radial styloid tenosynovitis

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2.2.3 Extensor Carpi Ulnaris Tendonitis 2.2.3.1 Overview The Extensor Carpi Ulnaris (ECU) is a thin muscle located in the posterior compartment of the forearm. Injury, usually secondary to repetitive or forceful wrist movement, results in ulnar-sided hand, wrist and forearm pain. 2.2.3.2 Pathogenesis The ECU originates from the distal humerus as part of the common extensor tendon and inserts on the base of the fifth metacarpal base. The tendon enters an osteofibrous sheath at the head of the ulna that passes deep to the extensor retinaculum prior to its insertion. Fascia overlies the osseous groove, forming the ECU subsheath. This is unique to the ECU when compared to the extensor compartments. The action depends on the position of the forearm, with extension and adduction of the wrist being predominant. It also contributes to medial wrist stability. Pathology can arise proximally or distally, the former being discussed later in the chapter in “Lateral epicondylitis.” Distal pathology arises from the unique anatomy of the ECU when compared to the other extensor tendons. The ECU is much more restricted in movement than the other extensor tendons, due in part to its separate subsheath which places varying amounts of stress depending on wrist positioning. Unlike the extensor retinaculum, which runs from the radius to carpal bones, and thus is not affected by supination or pronation, the subsheath has an ulnar attachment and thus varies with the aforementioned positions. With the wrist held in pronation, the angle of the ECU tendon as it exits the subsheath is approximately neutral. During supination, the ECU bends at the subsheath, reaching an angle of approximately 30° prior to attachment on its insertion point, as shown in Fig. 2.6. This also places the ECU in close proximity to the extensor digiti minimi and subjects it to maximal traction [18]. The ECU tendon sheath can be irritated by repetitive wrist movements, most commonly dorsiflexion and rotation of the

38 Fig. 2.6  With the forearm in pronation, the extensor carpi ulnaris (ECU) tendon exits its subsheath with a relative neutral angle. However, when the forearm is supinated and flexed when holding a controller, the tendon bends as it exits the subsheath

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wrist. Pain often develops where the tendon bends as it exits the fibro-osseous tunnel on the ulna. While ECU tendonitis is more commonly found in racket sports or following a Colles’ fracture, esports athletes are uniquely susceptible to injuries of this thin muscle. Non-neutral wrist positioning on keyboards or computer mice, such as dorsiflexion, places the tendon under increased and constant stress. Rapid wrist adduction, often required for “flick shots” and reaching more lateral keybinds, causes further microtrauma. Similarly, gaming controllers are often held with a partially supinated, flexed, and ulnarly deviated wrist, when the ECU is under maximal stress. With untreated and undiagnosed tendonitis, more serious tendinopathy can gradually develop. In rare cases, complications such as subluxation may occur. Subluxation occurs most commonly when the ECU is isometrically contracting with the wrist held in a position of supination, flexion and ulnar deviation, coupled with the application of a sudden force. Although this situation would be outside of the realm of normal esports, an accidental force being applied to a player’s hand while they are holding a controller could theoretically result in such an injury [19].

2.2.3.3 Presentation Patients with distal ECU tendonitis will often complain of dorsal, ulnar-sided wrist pain. Unless there was a presenting trauma, such as a fall or fracture, onset is most often insidious. Specific motions, such as ulnar deviation in extension, may worsen pain. “Keyboard holidays,” that is, extended periods of time not at their desk or setup, may result in alleviation of pain. In more advanced cases, patients may complain of loss of grip strength. If subluxation concurrently exists, patients may describe a sensation of clicking or popping as the wrist is actively moved into extension and supination. 2.2.3.4 Diagnosis Upon presentation, the clinical picture of ECU tendonitis may be hard to differentiate from injury to the triangular fibrocartilage complex (TFCC). Given the drastic difference in management,

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proper diagnostic procedures are necessary for successful outcomes. Physical Examination Due to the superficial nature of the ECU, slight swelling of the ulnar sheath may be visible, and palpation can easily locate the tendon. Patients with longstanding damage may have tenderness more proximally, up the length of the muscle, despite no subjective complaints of proximal symptoms. Depending on acuity, passive and active wrist extension and ulnar deviation may elicit discomfort. Similarly, resisted isometric supination can also provoke symptoms. Traditionally, resisted extension and ulnar deviation was used to diagnose ECU pathology. However, this position similarly loads the TFCC and is of little clinical value. Special testing can be the most useful to diagnose this clinical syndrome. ECU Synergy Test

The patient rests their arm on the examination table with the elbow flexed to 90° and the forearm held in maximal supination. The position of the wrist is neutral, and the fingers are in full extension. The examiner then grasps the patient’s thumb and index finger with one hand, while the other hand locates the ECU tendon. The patient then actively radially abducts the thumb against examiner’s resistance. The examiner confirms engagement of the ECU muscle contraction. Re-creation of pain along the dorsal ulnar aspect of the wrist is considered to be a positive test for ECU tendonitis [20]. Imaging Under ultrasound, the ECU is easily identified as it is the most superficial muscle on the ulnar side of the forearm. Ultrasound also offers the option of dynamic examination with supination and pronation. Peritendinous edema is usually present, with some degree of tendon thickening. For long-standing or severe cases, intratendon tears may be visualized.

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For refractory cases or when the differential is still uncertain, MRI can be utilized to properly visualize the involved structures.

2.2.3.5 Treatment Attention should be paid to a gamer’s keyboard, focusing on wrist neutrality in all planes. Bulky mechanical keyboards can place the wrist into extension, increasing tension in the ECU. A decreased keyboard slope has been associated with decreased activation of the ECU [21]. Therapeutic Modalities Splinting may be temporarily beneficial to reduce inflammation and pain. Splints that reduce radial and ulnar deviation are often chosen, with some placing the wrist in 30° of extension. Current literature suggests duration of use for approximately 4 weeks with removal for therapy. Exercises with light resistance and weight, as well as isometric holds can be performed to increase endurance and strength of affected musculature. Incorporating tendon and ulnar nerve glides may also be performed for further prevention and treatment. Pharmacological Management Oral and topical NSAIDs may be helpful for inflammation reduction and pain relief in the acute phases. Interventional Medicine For refractory symptoms or when immediate pain relief is necessary, a targeted corticosteroid injection to the area of dysfunction may provide relief. To ensure accuracy, ultrasound guidance is recommended. However, this may increase risk of tendon rupture, an uncommon but serious complication. In rare cases, surgical repair on the tendon and its sheath may be necessary [22].

2.2.4 Median Neuropathy at the Wrist Carpal tunnel syndrome

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2.2.4.1 Overview The median nerve is one of five main upper extremity nerves arising from the brachial plexus. It has multiple sensory and motor innervations, and is essential for proper upper extremity functioning. Nontraumatic compression of the median nerve can arise in multiple locations, such as the pronator teres and carpal tunnel of the wrist. Carpal tunnel syndrome (CTS) results from compression of the median nerve as it enters the hand inside of the carpal tunnel. This clinical syndrome results in tingling and numbness in a stereotypical distribution, as well as hand weakness. CTS is the most common nerve entrapment in the upper extremity. 2.2.4.2 Pathogenesis The carpal tunnel describes an anatomic compartment of the proximal hand that can be approximated superficially at the level of the distal wrist crease. It is bordered by carpal bones on three sides, and the transverse carpal ligament on the anterior side. The transverse carpal ligament is a fibrous band that runs medially from the pisiform laterally to the hamate, and is also known as the flexor retinaculum. The carpal tunnel contains nine flexor tendons and the median nerve. The median nerve is responsible for sensory innervation of the palmar surface of the thumb, index, middle finger, and lateral half of the ring finger, as well as the thenar eminence. It provides motor innervation to the flexor pollicis brevis, abductor pollicis brevis, and opponens pollicis, which are responsible for thumb flexion, abduction, and opposition. Being bound on three sides by bones and a fourth by a tough fibrous structure, the size of the carpal tunnel is relatively fixed. Similarly, the compressibility of the flexors tendons is inconsequential compared to that of the median nerve. As a result, when space becomes sparse inside the canal, the median nerve is the first to suffer. Canal space can be decreased by a variety of intrinsic or extrinsic factors, but most pertinent to the gaming population is via swelling or thickening of the flexor tendons and wrist positioning.

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Wrist positioning is an exceptionally important consideration for PC gamers. While a neutral wrist is optimal, due to large mechanical keyboards and thicker gaming mice the wrist is often held to some degree of extension. With wrist movements outside of neutral, carpal tunnel pressures have been measured almost 10 times that of normal [23, 24]. Mild compression can lead to a physiologic conduction block. This early nerve injury is usually completely recoverable as the endoneurium, perineurium, and epineurium are intact. However, with longstanding, repetitive damage myelin and the surrounding connective tissue framework may be disrupted, resulting in irreversible damage.

2.2.4.3 Presentation Numbness and tingling in the sensory distribution of the median nerve are often the first signs of CTS. Sensation to the thenar eminence and palm is spared, as the palmar cutaneous branch of the median nerve arises in the distal forearm, and does not traverse the carpal tunnel. Patients will complain of paresthesia which are often worse at night or upon awakening. This is often due to accentuated and sustained wrist flexion or extension while asleep. Neuropathic pain may accompany sensory disturbances, and it is not uncommon for patients to complain of symptoms proximal to the carpal tunnel. However, paresthesias that radiate into the neck should raise suspicion for an alternative diagnosis. Long-standing compression can lead to weakness in the muscles innervated by the median nerve. This can manifest as difficulty reaching keybinds on the right side of the keyboard, weakness when holding the controller, handwriting changes, difficulty with opening jars, or dropping cups. 2.2.4.4 Diagnosis There is no standardized set of diagnostic criteria for median neuropathy, but rather a constellation of symptoms and clinical findings. Electrophysiological testing can be quite useful.

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Physical Examination Inspection of the hands may reveal thenar eminence atrophy, which is a sign of severe, longstanding CTS. Sensory examination can elicit decreased sensation of the first three digits and stereotypical splitting of the ring finger. Examiners can compare the medial, ulnarly innervated side of the ring finger to the lateral, median innervated side. Weakness in the median innervated muscles can be found on motor testing, which are the flexor pollicis brevis, opponens pollicis, and abductor pollicis brevis. A variety of special testing also aids in clinical diagnosis.

Clinical Pearl

The median innervated hand muscles can be easily recollected using the LOAF acronym: Lumbricals 1 and 2, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis.

Phalen’s Maneuver

The patient’s wrists are placed into full flexion for a total of 60 s. While this is often taught with patient’s in the “reverse prayer pose,” the authors encourage extending the elbows forward as well. This avoids aggravation of any underlying cubital tunnel syndrome with elbow flexion, thus confounding the results. Carpal Compression Test

This test is performed by placing sustained direct pressure over the volar aspect of the wrist, directly over the carpal tunnel, for at least 30 s. The pressure can be held for up to 2 min. Both Phalen’s test and the carpal compression test are considered positive if paresthesia is generated in the distribution of the median nerve. These tests can be combined, as in Fig.  2.7, by placing compression over the median nerve while the patient’s wrists are held in complete flexion.

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Fig. 2.7  Combined Phalen’s Maneuver and Carpal Compression Test

Tinel’s at Wrist

To address the median nerve, light percussion is applied to the midline of the distal palmar crease. The test is considered positive if paresthesia is elicited in the first three digits. Imaging Ultrasound can be used to visualize the median nerve in the carpal tunnel. The presence of median nerve enlargement proximal to the carpal tunnel suggests a diagnosis of CTS. Electrodiagnostics Electrodiagnostics (EDX) may aid in diagnosis, but findings should not be taken in isolation. Up to 15% of patients with clinically diagnosed CTS may have normal EDX findings. Furthermore, severity of CTS symptoms does not always correlate with EDX findings. Sensory nerve conduction studies (NCS) are more sensitive than motor findings given their susceptibility to compression and ischemia. NCS will reveal slowing or a conduction block of the median nerve fibers across the carpal tunnel. EMG evaluation is targeted towards needle evaluation of the abductor pollicis brevis (APB). The APB may not be involved in mild cases of CTS, and

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thus EMG findings will be normal. However, with longstanding damage, EMG may reveal signs of axonal loss.5 EDX may also be used for severity grading. One of the most widely accepted neurophysiological grading scales is the Bland criteria, and ranks CTS from grade 0 (normal) to grade 6 (extremely severe). These grading scales may be helpful in selecting appropriate treatments, such as informing outcomes when deciding on surgical interventions [25, 26].

2.2.4.5 Treatment Therapeutic Modalities Treatment for mild cases begins with nocturnal wrist splinting. Most over-the-counter braces place the wrist in mild extension, which may need to be corrected. Other treatments include the use of kinesio tape during the day when performing repetitive tasks which is hypothesized to increase stability and off-load the carpal tunnel to relieve pain. Targeted occupational therapy includes median nerve glides and tendon glides, allowing for tendons and nerves to freely pass through the carpal tunnel. General wrist strengthening in pain-­ free movements can help increase wrist endurance. Manual therapy, mainly gradual gentle to deep massage of the forearm performed by a trained therapist, may also prove to be beneficial. Pharmacological Management For patients experiencing primarily neuropathic pain, gabapentin and other nerve medications can provide relief. Interventional Medicine An ultrasound-guided corticosteroid injection can be used to treat mild CTS symptoms. Severe cases that exhibit overt muscle atrophy or failure of conservative treatment most often require surgical release of the flexor retinaculum. However, patients with long-standing disease should be counselled that numbness and weakness may never resolve.

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2.2.5 Triangular Fibrocartilage Complex Injury Ulnar Impaction Syndrome

2.2.5.1 Overview The triangular fibrocartilage complex (TFCC) stabilizes the wrist and can be conceptualized as a homologue of the knee’s meniscus. While TFCC injuries in esports athletes are extremely rare, given the urgent need for intervention and similarity with ECU tendonitis, it warrants a brief mention. 2.2.5.2 Pathogenesis The TFCC is composed of the triangular fibrocartilage disc, radioulnar ligaments, and ulnocarpal ligaments. The primary function of the TFCC is load transmission across the ulnocarpal joint, and stabilization of the distal radioulnar joint and ulnocarpal articulations. The TFCC is the most commonly injured traumatically, with the wrist in extension and pronation and an axial load is applied. This is often seen after a fall on the outstretched hand. Degenerative tears are often seen in athletics and professions that rely on hand function, such as golfers, gymnasts, carpenters, and plumbers. As such, the latter can be extrapolated to be relevant to the gaming population. Ulnar variance, the relative distance between the articular surfaces of the distal radius and ulna, plays a large part in the load transmission from the wrist through the distal ulna. With increased ulnar variance, the load placed upon the TFCC increases. Similarly, wrist pronation also increases TFCC load [27]. 2.2.5.3 Presentation The primary symptom of a TFCC injury is often pain along the ulnar wrist, just distal to the ulnar styloid. Movements such as rotation (supination and pronation) and ulnar deviation often aggravate pain. Patients may frequently complain of pain when turning a door key or from using their hands to rise from a seated position. Other symptoms such as ulnar-sided wrist swelling, loss of grip strength, and crepitus may also be reported [28].

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2.2.5.4 Diagnosis Physical Examination Palpation in the soft spot between the ulnar styloid and flexor carpi ulnaris tendon may evoke tenderness, which is known as a positive “fovea” sign. Symptoms may also be provoked by compressing the joint with an axial load. This is performed by holding the forearm with one hand and placing the wrist in a position of ulnar deviation and extension with the other, subsequently compressing the joint. Imaging Plain anteroposterior radiographs are only useful if the etiology is traumatic or to calculate ulnar variance. MRI arthrography may be utilized if the diagnosis is unclear, and can detect TFCC tears on T1-weighted imaging. Fluid may also appear in the distal radioulnar joint. Arthroscopy is the most accurate method of diagnosis. Ultrasonographic evaluation of the TFCC can be challenging. It normally appears as a hyperechoic triangular-shaped structure that comes into contact with the triquetrum. Injury may be represented as subtly as abnormal hypoechogenicity, thinning, or absence entirely [29].

2.2.5.5 Treatment Therapeutic Modalities For mild cases with no wrist instability, a TFCC splint can be utilized for a duration of 4 weeks. General wrist, grip, and forearm strengthening exercises, along with stretching can help reduce the risk of injury [30]. Interventional Medicine If pain persists beyond 4 weeks, referral to a hand surgeon may be necessary. Similarly, if MRI reveals injury to the central articular disc of the TFCC or if wrist instability is present, surgery is the treatment of choice [31].

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2.2.6 Thumb Carpometacarpal Arthritis 2.2.6.1 Overview Osteoarthritis of the first carpometacarpal (CMC) joint is a common disease in patients over the age of 50. However, due to the increased use and pressures placed on the gamer’s thumb, this pathology may have a higher prevalence in the younger esports population. 2.2.6.2 Pathogenesis The CMC joint is a saddle joint created by the articulation of the first metacarpal with the trapezium bone. It lacks bony confinement, placing increased importance on the surrounding ligaments for stabilization. The anterior ligament, known as the beak ligament, is the most important stabilizer. Laxity of the beak ligament can lead to increased stress loads on the CMC joint. 2.2.6.3 Presentation Patients often complain of diffuse thumb pain that is typically difficult to localize. It may be aggravated by positions that require sustained flexion, such as use of a controller, buttoning, pinching, grasping, or turning a key. Swelling, stiffness, crepitus, and weakness may also be presenting symptoms. 2.2.6.4 Diagnosis Physical Examination Inspection can reveal metacarpal base enlargement, resulting in a visible deformity. Palpation of the volar aspect of the CMC joint usually elicits tenderness. Strength testing may reveal weakness in thumb flexion that is due to pain and disuse rather than inherent muscle weakness. Grind Test

Axial load is placed on the CMC joint from the distal thumb, while introducing slight rotation. A positive test is signified by pain or crepitus.

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Imaging X-ray reveals early findings of osteoarthritis, such as joint space narrowing. With longer-standing cases, later signs of osteoarthritis such as osteophytes, subchondral sclerosis, and cysts may be present [32].

2.2.6.5 Treatment Given the younger patient population in esports, treatment should largely focus on prevention of CMC injury. While there is a lack of relevant data on this specific injury in our target population, understanding of the pathophysiology points towards a probable future prevalence. Osteoarthritis of any joint is largely irreversible. However, with rehabilitation and symptom management, most patients can achieve some degree of pain-free motion. Treatment should be focused on symptom management and prevention of progression. Therapeutic Modalities Splinting, either with a custom design or over-the-counter thumb splint at night or on a wearing schedule can result in reasonable pain relief. This can be of particular benefit during acute flares. Strengthening exercises and joint ROM can help desensitize the joint’s innervating nerves, allowing for increased use while decreasing sensitivity to pain. Use of hot and cold packs can help alleviate pain, or aid in muscle relaxation before completing aggravating tasks. Pharmacological Management NSAIDs, either topical or oral, may be utilized to address pain and decrease swelling. Interventional Medicine For moderate disease, corticosteroid injections can be beneficial for pain relief. However, repetitive injections may lead to joint weakening. Hyaluronic acid injections have shown no relief in pain or improved functioning when compared to corticosteroids [33].

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Surgery is an option for end-stage cases refractory to conservative care [34].

2.2.7 Radial Sensory Neuritis Wartenberg syndrome, Handcuff neuropathy, cheiralgia paresthetica

2.2.7.1 Overview Irritation of the radial sensory nerve can occur alone, or in conjunction with radial styloid tenosynovitis. As a purely sensory nerve, this syndrome presents without motor symptoms. 2.2.7.2 Pathogenesis The superficial branch of the radial nerve (RSN) arises in the proximal forearm from the bifurcation of the radial nerve. It then courses deep to the brachioradialis, travelling through the deep fascia, and emerges around 10 cm proximal to the radial styloid between the brachioradialis and ECRL in the dorsal compartment. Near its terminal end, it courses close to the skin. The nerve itself then bifurcates, with the dorsal branch supplying sensory innervation to the first and second web space and palmar branch supplying sensory innervation to the dorsolateral thumb. The sensory distribution is shared with the median nerve and dorsal ulnar cutaneous nerve. This is clinically important as a pure sensory deficit might be difficult to localize. The nerve can be compressed either internally or externally. During repetitive wrist and thumb movements, the sensory radial nerve can become compressed between the brachioradialis and ECRL tendons. Similarly, wristwatches, bracelets, or compression gloves may serve as an extrinsic cause of injury. With the advent of nonscientifically backed performance gloves in the esports sphere, this syndrome is of particular clinical importance [35].

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2.2.7.3 Presentation Patients may complain of radiating pain as well as sensory deficits, paresthesias, and dysesthesia across the thumb and dorsoradial hand. Pain is often ill-defined and poorly localized. Symptoms often worsen with wrist flexion and ulnar deviation. Patients may also state they no longer wear bracelets and wristwatches as a result. For teams with long-sleeved jerseys, clinicians may pick up on competitors rolling up one sleeve over the other [36]. Clinical Pearl

RSN can be associated with radial styloid tenosynovitis in up to half of cases [37].

2.2.7.4 Diagnosis As the radial sensory nerve is purely sensory, any motor involvement that is found on physical exam should point to another, more proximal etiology. Physical Examination Sensory examination will reveal decreased or abnormal sensation in the dorsal thumb and dorsal radial hand. Given the overlapping dermatomes of the hand, the dorsal web space of the thumb can be most precise to localize purely RSN lesions. If the cause is secondary to concurrent radial styloid tenosynovitis, then Finkelstein’s test may also be performed.

Clinical Pearl

Radial Sensory Neuritis Versus • Radial Styloid Tenosynovitis. RSN is often aggravated by pronation, where tenosynovitis is aggravated by ulnar deviation. • Intersection syndrome: RSN will not present with crepitus with wrist flexion/extension.

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Tinel’s Test

There may be a positive Tinel’s sign over the radial sensory nerve. Hyperpronation Provocative Testing

With the wrist held in ulnar deviation, the forearm is pronated. Paresthesias in the distribution of the RSN signifies a positive test. Imaging Imaging and electrodiagnostics are of little use. When the diagnosis is unclear, a diagnostic wrist block of the RSN can be performed. The test would be considered positive if it provides temporary symptomatic relief. Electrodiagnostics Patients with purely radial sensory neuritis may have abnormal sensory nerve conduction values on NCS. They should have otherwise normal NCS and EMGs, and abnormality would point in the direction of an alternative diagnosis [38].

2.2.7.5 Treatment Given that the nerve is purely sensory, numbness is the only clinical consequence of lack of treatment. As such, options that offer more complicated risks should be avoided. If the neuritis arises secondary to radial styloid tenosynovitis, treatment of the causative factor should take precedent. Therapeutic Modalities A thumb spica splint may alleviate painful dysesthesia. However, a splint that is too tight may worsen symptoms. Patients should be instructed to avoid tight clothing and watches. Implementing a routine, including radial and median nerve glides, not to exceed more than 10 individual glides a day, can help prevent RSN. These exercises reinforce the proper pathway for the nerve and other structures to decrease the risk of entrapment or compression [36].

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2.3

Elbow

2.3.1 Ulnar Neuropathy Cubital Tunnel Syndrome, Guyon’s Canal Syndrome, Funny Bone

2.3.1.1 Overview The ulnar nerve is the largest unprotected nerve in the human body, leaving it susceptible to damage in a multitude of places. Ulnar neuropathy can occur both at the wrist and the elbow, with the latter being far more common, and is the second most common compression neuropathy. The ulnar nerve provides motor innervation to part of the forearm and majority of the hand, as well as sensory innervation to the hand. 2.3.1.2 Pathogenesis As the ulnar nerve courses from its origin at the medial cord of the brachial plexus to its terminal destination, there are a multitude of possible places for entrapment or compression. In the upper arm, the ulnar nerve pierces the Arcade of Struthers, a musculoaponeurotic canal and site of potential pathology. It then travels distally along the humerus and enters the retrocondylar groove, also known as the cubital tunnel. The tunnel is bound by the flexor carpi ulnaris muscle, humeroulnar arcade, and medial elbow ligaments. This site is the most common area of compression, due in part to its dynamic size with elbow movement. Of note, some authors choose to separate the retrocondylar groove from the cubital tunnel. However, for the scope of this book, they will be discussed as a similar structure. With elbow flexion, the space between the medial epicondyle and olecranon increases by up to 1 cm. Subsequently, the humeroulnar arcade tightens down upon the ulnar nerve. At the same time, the medial elbow ligaments bulge and flatten the floor of the normally deep retrocondylar groove, while the medial head of the triceps muscle pushes the nerve posteriorly. When the elbow is in complete flexion, the nerve is pulled tight around the medial epicondyle. This is a significantly different

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orientation from extension, during which the ulnar nerve is freely movable. Compression or damage at this site is labeled cubital tunnel syndrome. In the esports population, this is usually a result of chronic mechanical compression from arm rests and desks or stretch from chronic elbow flexion. It can also result from a fracture of the medial epicondyle of the humerus (causing direct ulnar nerve injury) or fracture of the lateral epicondyle of the humerus, which may result in a valgus deformity at the elbow. The nerve then pierces the aponeurosis lining the deep heads of the flexor carpi ulnaris and runs between the tendons and muscle planes of the medial forearm to the wrist. In the mid-forearm, two sensory branches arise from the ulnar nerve, the palmar cutaneous branch and dorsal cutaneous branch, and course distally, avoiding the Guyon canal. The former ­supplies the cutaneous territory over the proximal border of the ulnar portion of the palm. The latter supplies the ulnar side of the dorsum of the hand and dorsal surfaces of the fifth and ulnar half of the fourth digit. The ulnar nerve enters the hand via Guyon’s canal, along with the ulnar artery, which is bound superficially by the flexor retinaculum and medially by the pisiform bone. As the nerve exits the groove, it passes under the aponeurotic arch of the humeroulnar arcade (a derivative of the flexor carpi ulnaris muscle). The roof of Guyon’s canal consists of the palmar fascia and the palmaris brevis muscle. The nerve may also be compressed at this location, either directly from the surface of a desk or a Guyon’s canal cyst. The ulnar nerve provides sensory innervation to the fifth digit and medial half of the fourth digit, as well as dorsal medial hand and medial forearm. It also provides motor innervation to a number of forearm and hand muscles, most relevantly the forearm flexors, including the muscles of the hypothenar eminence [39].

2.3.1.3 Presentation Sensory and motor complaints distal to the site of compression are the hallmarks of ulnar nerve damage. Numbness or paresthesia in the medial forearm that radiates into the pinkie and ring

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finger are common complaints. Patients may not initially be able to localize the specific involved digits initially, but are often more successful when more targeted questions are presented. Sensory changes can be localized over the hypothenar eminence, as well as the ulnar half of the palm, fifth and medial half of the fourth digit. These can manifest as paresthesia and numbness. Patients may also complain of pain, which is more commonly around the elbow. Symptoms are often worse at night or with repetitive elbow/wrist movements. Motor weakness present can be subclinical. Patients with severe compression or transection can complain of weakness in wrist flexion or be unable to cross their fingers. Weakness of the pinkie finger may result in difficulty placing the little finger into their pocket. Ulnar lesions at the elbow typically present with numbness and tingling in the fourth and fifth digits, medial elbow pain, nocturnal numbness and paresthesia, and worsening of symptoms with elbow and/or repeated wrist flexion. Ulnar lesions at the wrist typically present with hand weakness and atrophy, loss of dexterity, and variable sensory involvement as outlined below. Sensory symptoms from ulnar neuropathy at the elbow are often brought on by sustained elbow flexion (e.g., when talking on the phone or lying on one’s side with the elbow flexed). Symptoms can also be provoked by leaning on the elbow or when performing activity that requires sustained or repetitive grip, or repeated forearm pronation and supination). Patients may complain of weakness and clumsiness of the hands, most specifically in activities that require hand dexterity, such as their keyboard hand or when buttoning [40].

Clinical Pearl

Loss of dexterity due to ulnar neuropathy is usually indicative of weakness of the intrinsic hand muscles in contrast to mild median nerve injury, where loss of dexterity is most often related to sensory loss.

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2.3.1.4 Diagnosis The diagnosis of ulnar neuropathy at the elbow or wrist can be made clinically via effective history taking and a thorough physical examination. If the clinical picture is uncertain, electrodiagnostics and imaging may be necessary. Physical Examination Inspection can reveal interossei and hypothenar eminence atrophy. Some degree of thenar eminence atrophy may also be present, secondary to wasting of the ulnar-innervated adductor pollicis and deep head of the flexor pollicis brevis. With long-standing damage, a claw hand deformity, also known as Benediction posture, can develop at rest. This results from hyperextension of the 4th and 5th digits and the metacarpophalangeal joints and flexion of the interphalangeal joints. This is more common with injuries at the wrist as opposed to the upper arm, as the ulnar half of the flexor digitorum profundus is spare, pulling the DIP joints into a more flexed position (also known as ulnar paradox). Inspection may also reveal Wartenberg’s sign, which is the little finger held into abduction secondary to weakness. The ulnar nerve can be palpated in the elbow region, with special attention being paid for any swelling or masses. Subluxation can be assessed over the medial epicondyle, while flexing and extending at the elbow. Examiners may feel a snapping sensation. A sensory examination may reveal diminished sensation over the aforementioned regions, and splitting of the fourth digit. Injury to the ulnar nerve at the wrist can produce remarkably different clinical pictures depending on the area of damage. Injury to the ulnar nerve, before it divides into smaller tributaries in Guyon’s canal, will have broader sensory consequences and affect all ulnar innervated intrinsic hand muscles. Distal to Guyon’s canal, injuries to the deep terminal motor branch and superficial terminal branch will have varying clinical consequences, outside the scope of this textbook.

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Tinel’s Test

To perform, sustained, light percussion is applied to the ulnar nerve at the elbow or wrist. Paresthesias along the distribution of the nerve is considered a positive test. Froment’s Sign

The patient is instructed to pinch a sheet of paper between their thumb and pointer finger while holding the thumb IP joint in extension. Patients with ulnar nerve damage and subsequent weakness of the adductor pollicis will flex their fingers in order to maintain grip strength, thus compensating with their median-­ nerve innervated flexor pollicis longus. Patients with a positive Fromen’s sign will be unable to hold the extended thumb posture, as shown in Fig. 2.8. Imaging Advanced imaging is useful when the clinical picture is murky, and may be particularly helpful when masses (such as ganglion cysts) are present. Ultrasound examination may reveal altered echogenicity, enlargement and entrapment of the nerve, and transposition. Enlargement of the nerve proximal to the site of entrapment is a common finding. After the ulnar nerve is localized at the elbow, the arm can be flexed and extended to assess for possible subluxation. One study suggests that sonographic evaluation of ulnar neuropathy of the elbow based upon nerve diameter may have a sensitivity and specificity of 80 and 91% compared to clinical and electrodiagnostic criteria alone. When compared to electrodiagnostic diagnosis, another study showed a sensitivity and specificity of 95% and 71%. MRI may reveal increased signal intensity on T2-weighted or STIR imaging sequences as well as increased size of the ulnar nerve [41, 42].

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a

b

Fig. 2.8 (a) Normal thumb adduction (b) Positive Froment’s sign, as signified by flexion of the thumb’s interphalangeal joint

Electrodiagnostics Nerve conduction studies are relatively straightforward in the evaluation of ulnar neuropathy. Abnormalities may be found when testing ulnar sensory responses to the fifth digit, or when testing motor studies are recorded to the abductor digiti minimi. For equivocal results around the elbow, an “inching” technique can be applied, also known as short segment incremental studies. This can be helpful in locating the exact location of the lesion. Furthermore, dual channel studies may be done by recording over the ADM and first dorsal interosseous (FDI) simultaneously. The FDI destined nerve fibers run more peripherally across the elbow, placing them at a higher risk for compression.

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2.3.1.5 Treatment Therapeutic Modalities If the inciting trauma is found to be extrinsic compression from position while gaming, elbow pads can aid in both prevention of aggravation and treatment. Pads are placed on the dorsal-medial elbow during waking hours to prevent compression over the medial epicondyle. This can then be rotated to the ante-cubital fossa at night, thereby preventing excessive flexion. A simple towel can also be utilized during sleep hours to the same effect. Activity modification is equally as important for ulnar neuropathy at the wrist. Padded gloves may be utilized, or a wrist rest that avoids direct compression to Guyon’s canal. Referral to an occupational therapist may also include incorporation of nerve gliding exercises as well as soft tissue release of the forearm [43]. Pharmacological Management The role of pharmacological management is limited in ulnar neuropathy. Oral NSAIDs may be helpful in acute phases for pain control. Interventional Medicine In severe cases, the nerve may need to be surgically released from its area of entrapment. Surgery is often indicated for patients with clear weakness, sensory loss, or signs of denervation on EMG. Surgery of the elbow usually includes simple decompression by cutting the humeroulnar arcade (flexor carpi ulnaris aponeurosis) or transposition. The latter is performed by first cutting the aponeurosis and then mobilizing the ulnar nerve anteriorly from the retrocondylar groove. In severe cases, a medial epicondylectomy may be performed. Most of the available data for ulnar neuropathy at the elbow suggest that ulnar nerve decompression and transposition result in similar clinical outcomes, though transposition may be hampered by higher rates of complications. On top of lower rates of complications, decompression procedures are faster and less technically demanding [44, 45].

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2.3.2 Lateral Epicondylitis Tennis elbow, elbow tendinopathy, lateral epicondylalgia, elbow tendonitis

2.3.2.1 Overview The lateral epicondyle of the elbow is the bony origin for the majority of the wrist extensors. Pain at the myotendinous junction of these muscle groups is referred to as lateral epicondylitis. This diagnosis was initially described in 1883 associated with lawn tennis, but this chronic tendinosis is of increasing concern in the gaming population due to its association with repetitive or dysfunction wrist extension. 2.3.2.2 Pathogenesis The lateral epicondyle is an extra-articular bony prominence on the distal humerus that serves as the common origin of the wrist extensors. The most common involved muscle is the extensor carpi radialis brevis muscle (ECRB) followed by the extensor digitorum communis muscle (EDC). Involvement of the extensor carpi radialis longus or extensor carpi ulnaris is rare. Despite the -itis suffix, histological examination of epicondylitis reveals very few inflammatory cells. Evidence suggests that epicondylitis is not an acute inflammatory reaction, but rather a result of chronic tendinosis. Eccentric movement, referring to any movement that lengthens a muscle at the same time it is being contracted, is the most common indicated mechanism of injury. Chronic, repetitive eccentric motion can lead to disorganized tissue structure, placing the muscle at further risk for injury [46]. 2.3.2.3 Presentation Pain in the lateral elbow is the most common presenting symptom, often exacerbated by wrist and elbow movement as well as radial deviation. Patients with epicondylitis typically complain of extra-articular elbow pain. The pain’s severity can range from having a minimal effect on sports or work activities to severely impairing basic daily tasks and sleep.

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Symptom onset is traditionally gradual, with aggravating after specific activities that involve gripping and wrist extension. Players may complain of pain in either their keyboard or controller hands, and it may worsen when reaching thumb-sided keybinds. Symptoms are worsened after long gaming sessions that do not involve scheduled breaks.

2.3.2.4 Diagnosis Physical Examination Palpation can elicit pain at the lateral epicondyle and immediate wrist extensor muscle mass. The ECRB can be palpated just at the tip of the lateral epicondyle, and the EDC posterior and distal to that. Range of motion testing can reveal pain with passive wrist flexion to end range. Resisted wrist extension, third digit extension, pronation, and supination may also cause discomfort. Cozen’s Test

The patient’s arm is placed in a position of complete elbow extension and forearm pronation with a clenched fist. The examiner stabilizes the elbow with one hand while palpating the lateral epicondyle, and the other hand is placed on the dorsum of the patient’s hand. The patient then extends and radially deviates the wrist. Pain over the lateral epicondyle represents a positive test. Clinical Pearl

The fingers are flexed in a fist to avoid involvement of the extensor digitorium origin. Similarly, radial counterforce is also applied by the examiner to avoid involvement of the extensor carpi ulnaris and confounding by concurrent ECU tendonitis.

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Imaging Imaging should be reserved for cases refractory to conservative management, and is not necessary for straightforward diagnoses. Three-view x-ray series may reveal underlying bony abnormalities, such as long-standing osteoarthritic changes or heterotopic ossification. Musculoskeletal ultrasound can identify abnormal tendon appearance (e.g., tendon thickening, partial tear at tendon origin, calcifications). MRI may reveal increased signal intensity on T2 weighted images in ECRB [47].

2.3.2.5 Treatment Therapeutic Modalities Activity modification, counterforce bracing, NSAIDs, and physical therapy are the mainstays of treatment. Without intervention, epicondylitis can take upwards of two years to resolve. Counterforce bracing may provide benefit in acute flares by reducing the stress on the muscular insertion point. This circular brace is placed approximately 6–10 cm distal to the elbow joint. Studies conducted by independent researchers and not manufacturer-­supported are scant, but bracing may reduce pain and, therefore, contribute to functionality. Splinting with a volar wrist splint is of little use and has not been found to be more effective than a counterforce brace, but is significantly more cumbersome. Splinting may also be associated with poorer outcomes. Physical and occupational therapy focused on progressive eccentric strengthening may also be effective. Both the extensor and supinator groups should be targeted. Common utilized exercises include utilizing wrist flexion with resistance band, going from complete extension to complete flexion. Gamers should be encouraged to warm up prior to play, focusing on range of motion exercises, as well as self-massage their forearm muscles to reduce stiffness [48–50].

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Pharmacological Management Oral NSAIDs may be indicated in the short term to reduce pain and improve function, but caution must be taken for long-term usage given the propensity of side effects. Topical NSAIDs may provide some symptomatic relief given the superficial nature of the indicated structures. Interventional Medicine If standard interventions prove unsuccessful, more aggressive interventions can be pursued. However, if imaging has not yet been obtained, further diagnostics may be indicated. Corticosteroid injections have been shown to lead to worse long-term outcomes and do not prevent recurrences, and should be considered in cases where immediate pain relief is the primary concern. While short-term pain relief may be better when compared to no injection, it has been associated with a higher rate of recurrence [50, 51]. “Peppering,” a technique in which the tendon is injected upwards of 50 times, is an interesting approach that has been shown to lead to better outcomes than placebo. Results found were independent of medication administered, suggesting the effect is related to the injection technique rather than the injectable. This intervention may be deemed beneficial via an invoked inflammatory response, similar to PRP injections discussed later [52]. As mentioned previously, lateral epicondylitis is a chronic condition resulting in disorganized tissue architecture. A growing field of treatment, known as “proinflammatory” has been proposed to reverse these chronic changes by stimulating the inflammatory response. These interventions are still in their infancy, and as a result, lack high-quality research studies. Platelet-rich plasma injections thought to be rich in growth factors that will theoretically stimulate tissue repair have been utilized by regenerative medicine proponents [53]. Other interventions have been proposed and have varying degrees of efficacy. There is no evidence that extracorporeal shock wave therapy or acupuncture produce long-term benefits. Studies

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addressing the use of botulinum toxin A at the myotendinous junction have shown a reduction in symptoms without decreases in grip strength. Prolotherapy, injecting an irritant, such as dextrose, in an effort to simulate a local inflammatory response, has also been utilized [54, 55].

2.3.3 Olecranon Bursitis 2.3.3.1 Overview The olecranon bursa is a fluid-filled sac overlying the posterior elbow designed to reduce joint friction. Inflammation of that sac can occur with longstanding microtrauma, such as leaning on the elbow, resulting in painless swelling. Of minimal clinical significance, this pathology will be discussed briefly. 2.3.3.2 Pathogenesis Normal bursa are essentially empty sacs, with almost no, or only a small amount of fluid present. Under physiological conditions, the bursa serves to reduce joint friction. In pathological states, the bursa becomes inflamed, subsequently increasing fluid production. Increased fluid causes the cavity to swell, ballooning out. Bursitis most commonly develops from trauma. One single injury to the elbow is more common in the general population. In the gaming population, a buildup of microtraumas from constant pressure on the olecranon during gaming is a more common etiology. 2.3.3.3 Presentation Patients will commonly present with swelling over the posterior olecranon process. This is most often painless swelling, but can present with pain or redness. 2.3.3.4 Diagnosis Physical Examination The bursa is located over the proximal end of the ulna on the extensor aspect. Normal, non-inflamed bursa are usually not able

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to be palpated. A palpable bursa is the most obvious sign of bursitis. The olecranon bursa is an extra-articular structure; therefore, the fluid buildup is not in the joint. As a result, range of motion will not be affected. Superficial skin lesions may indicate infection of the bursa, a condition that may warrant fluid aspiration and testing. Imaging A thorough physical examination should be the only necessary diagnostic step.

2.3.3.5 Treatment Therapeutic Modalities Prevention of further microtraumas should be the mainstay. An evaluation of a player’s setup may be necessary if the bursitis does not resolve quickly. PC gamers should be encouraged to rest their forearms on their desk, rather than the elbows directly. Console gamers may similarly be assuming a more acute elbow flexion angle, thus placing increased pressure on the bursa. Education and prevention may fully resolve the swelling. If further intervention is necessary, compression may help reduce inflammation and encourage fluid reduction [55].

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33. Kroon FP, Rubio R, Schoones JW, Kloppenburg M. Intra-articular therapies in the treatment of hand osteoarthritis: a systematic literature review. Drugs Aging. 2016;33(2):119–33. https://doi.org/10.1007/s40266-­015-­ 0330-­5. 34. Ghavami A, Oishi SN.  Thumb trapeziometacarpal arthritis: treatment with ligament reconstruction tendon interposition arthroplasty. Plast Reconstr Surg. 2006;117(6):116e–28e. https://doi.org/10.1097/01. prs.0000214652.31293.23. 35. Han BR, Cho YJ, Yang JS, Kang SH, Choi HJ. Clinical features of wrist drop caused by compressive radial neuropathy and its anatomical ­considerations. J Korean Neurosurg Soc. 2014;55(3):148–51. https://doi. org/10.3340/jkns.2014.55.3.148. 36. Wang LH, Weiss MD.  Anatomical, clinical, and electrodiagnostic features of radial neuropathies. Phys Med Rehabil Clin N Am. 2013;24(1):33– 47. https://doi.org/10.1016/j.pmr.2012.08.018. 37. Lanzetta M, Foucher G. Entrapment of the superficial branch of the radial nerve (Wartenberg’s syndrome). A report of 52 cases. Int Orthop. 1993;17(6):342–5. https://doi.org/10.1007/BF00180450. 38. Frontera WR. Cyclist’s palsy: clinical and electrodiagnostic findings. Br J Sports Med. 1983;17(2):91–3. https://doi.org/10.1136/bjsm.17.2.91. 39. Padua L, Aprile I, Caliandro P, Foschini M, Mazza S, Tonali P. Natural history of ulnar entrapment at elbow. Clin Neurophysiol. 2002;113(12):1980–4. https://doi.org/10.1016/s1388-­2457(02)00295-­x. 40. Frost P, Johnsen B, Fuglsang-Frederiksen A, Svendsen SW. Lifestyle risk factors for ulnar neuropathy and ulnar neuropathy-like symptoms. Muscle Nerve. 2013;48(4):507–15. https://doi.org/10.1002/mus.23820. 41. Bayrak AO, Bayrak IK, Turker H, Elmali M, Nural MS. Ultrasonography in patients with ulnar neuropathy at the elbow: comparison of cross-­ sectional area and swelling ratio with electrophysiological severity. Muscle Nerve. 2010;41(5):661–6. https://doi.org/10.1002/mus.21563. 42. Beekman R, Schoemaker MC, Van Der Plas JP, et al. Diagnostic value of high-resolution sonography in ulnar neuropathy at the elbow. Neurology. 2004;62(5):767–73. https://doi.org/10.1212/01.wnl.000011 3733.62689.0d. 43. Caliandro P, La Torre G, Padua R, Giannini F, Padua L. Treatment for ulnar neuropathy at the elbow. Cochrane Database Syst Rev. 2016;11(11):CD006839. https://doi.org/10.1002/14651858.CD006839. pub4. 44. Brown JM, Yee A, Mackinnon SE. Distal median to ulnar nerve transfers to restore ulnar motor and sensory function within the hand: technical nuances. Neurosurgery. 2009;65(5):966–78. https://doi.org/10.1227/01. NEU.0000358951.64043.73. 45. Davidge KM, Yee A, Moore AM, Mackinnon SE. The supercharge end-­ to-­side anterior interosseous-to-ulnar motor nerve transfer for restoring

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intrinsic function: clinical experience. Plast Reconstr Surg. 2015;136(3):344e–52e. https://doi.org/10.1097/PRS.0000000000001514. 46. Cohen M, da Rocha Motta Filho G. Lateral epicondylitis of the elbow. Rev Bras Ortop. 2015;47(4):414–20. https://doi.org/10.1016/S2255-­ 4971(15)30121-­X. 47. Chen AL, Youm T, Ong BC, Rafii M, Rokito AS. Imaging of the elbow in the overhead throwing athlete. Am J Sports Med. 2003;31(3):466–73. https://doi.org/10.1177/03635465030310032601. 48. Hoogvliet P, Randsdorp MS, Dingemanse R, Koes BW, Huisstede BM. Does effectiveness of exercise therapy and mobilisation techniques offer guidance for the treatment of lateral and medial epicondylitis? A systematic review. Br J Sports Med. 2013;47(17):1112–9. https://doi. org/10.1136/bjsports-­2012-­091990. 49. Van De Streek MD, Van Der Schans CP, De Greef MH, Postema K. The effect of a forearm/hand splint compared with an elbow band as a treatment for lateral epicondylitis. Prosthetics Orthot Int. 2004;28(2):183–9. https://doi.org/10.1080/03093640408726703. 50. Croisier JL, Foidart-Dessalle M, Tinant F, Crielaard JM, Forthomme B.  An isokinetic eccentric programme for the management of chronic lateral epicondylar tendinopathy. Br J Sports Med. 2007;41(4):269–75. https://doi.org/10.1136/bjsm.2006.033324. 51. Olaussen M, Holmedal O, Lindbaek M, Brage S, Solvang H.  Treating lateral epicondylitis with corticosteroid injections or non-­ electrotherapeutical physiotherapy: a systematic review. BMJ Open. 2013;3(10):e003564. https://doi.org/10.1136/bmjopen-­2013-­003564. 52. Mishra AK, Skrepnik NV, Edwards SG, et  al. Efficacy of platelet-rich plasma for chronic tennis elbow: a double-blind, prospective, multicenter, randomized controlled trial of 230 patients. Am J Sports Med. 2014;42(2):463–71. https://doi.org/10.1177/0363546513494359. 53. Espandar R, Heidari P, Rasouli MR, et al. Use of anatomic measurement to guide injection of botulinum toxin for the management of chronic lateral epicondylitis: a randomized controlled trial. CMAJ. 2010;182(8):768– 73. https://doi.org/10.1503/cmaj.090906. 54. Scarpone M, Rabago DP, Zgierska A, Arbogast G, Snell E. The efficacy of prolotherapy for lateral epicondylosis: a pilot study. Clin J Sport Med. 2008;18(3):248–54. https://doi.org/10.1097/JSM.0b013e318170fc87. 55. Reilly D, Kamineni S.  Olecranon bursitis. J Shoulder Elb Surg. 2016;25(1):158–67. https://doi.org/10.1016/j.jse.2015.08.032.

3

Neck and Back Disorders in Esports Lindsey Migliore and Caitlin McGee

3.1

Overview

Nonspecific, also known as mechanical, back pain is one of the most frequently encountered medical conditions and will be experienced by >85% of people during the course of their lifetime. As with any other joint of the body, the spine gradually degenerates with age. However, due to poor posture and ergonomic negligence, the gaming population may be at higher risk for early degeneration. While the source of pain in this population may commonly be the mundane and benign myofascial origin that requires no advanced imaging or interventions, it still requires aggressive provider involvement. Focus should be paid on ergonomic interventions, informed counselling, and tailored exercise programs to prevent acute processes from advancing into chronic [1]. In a case study of college esports athletes, 42% of players experienced neck or back pain [2]. Extended desk times, poor

L. Migliore (*) GamerDoc, Washington, DC, USA e-mail: [email protected] C. McGee 1HP, Washington, DC, USA © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 L. Migliore et al. (eds.), Handbook of Esports Medicine, https://doi.org/10.1007/978-3-030-73610-1_3

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posture, core weakness, and inactivity can compound and predispose patients to a multitude of degenerative changes. Because the field of esports medicine is in its infancy, practitioners must rely on their knowledge of anatomy and pathophysiology when the precedent fails them and research studies are absent.

3.1.1 Anatomy The vertebral column is a major component of the axial skeleton composed of 24 bony vertebrae separated by intervertebral discs. Vertebrae are named according to their spinal region, with 7 cervical, 12 thoracic, 5 lumbar, 5 fused sacral, and 4 fused coccyx components. Each vertebrae contains structures intended for joint articulation and muscle attachments, as well as openings, called foramina, for spinal nerve roots. The vertebrae are anatomically divided into two parts: the anterior vertebral body and posterior vertebral arch. The posterior vertebral arch houses and protects the spinal cord, and is formed by two pedicles, two laminae, and seven processes (one spinous, two transverse, and four articular). Facet joints, also known as zygapophyseal or apophyseal joints, are true synovial joints formed between the articular processes of two adjacent vertebrae. Each facet joint contains a capsule, meniscus, and synovial membrane. Facet joints, shown in Fig.  3.1, guide movement of their corresponding spinal segment and provide stabilization. The facet joint has nociceptive receptors in both the capsule and synovium. Each joint receives dual innervation from medial branches of the dorsal primary ramus of the corresponding spinal nerve. Facet joints in the cervical spine are innervated by the same level, and the level below, whereas those in the thoracic and lumbar spine are innervated by the same level and level above. The one notable exception is the L5–S1 joint, which receives innervation from the medial branch of L4 and the dorsal ramus of L5 [3]. The lower cervical spine vertebrae (C3–7) have additional articulations called the uncovertebral joints, or joints of Luschka. These joints are common locations of osteoarthritis, which

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Vertebral body

Intervertebral disc

Fig. 3.1  Sagittal view of the spinal column depicting the vertebral body of the spinal cord, separated by intervertebral discs. Facet joints are formed between the articular processes of two adjacent vertebrae

n­ arrows their corresponding intervertebral foramina. Thus, the most common locations of the cervical spine that exhibit degenerative changes are between C4–C7 [4]. Intervertebral or neural foramen are small openings between adjacent segments that serve as the exit site of the corresponding spinal nerve root. The foramen directly abut both the intervertebral disc and facet joint. Spinal ligaments run longitudinally, serving as strong fibrous bands that stabilize the spine. The three major ligaments are the anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), and ligamentum flavum. The intervertebral disc is composed of a viscous inner nucleus pulposus and outer annulus fibrosus. The nucleus pulposus is a gelatinous structure that is 90% water at birth. The annulus fibrosus consists of type I collagen fibers arranged obliquely that are anchored onto vertebral endplates. This fiber arrangement allows the annulus to withstand motion in most planes, but places it at risk for torsional injuries. A major function of the disc is shock absorption. The liquid nucleus pulposus is predominantly incompressible, and disc pressure subsequently results in stretching of the annulus fibers.

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Discs Under Pressure

While facet joints provide some rotational resistance with a neutral spine, they cannot provide counterpressure with the spine in flexion, thus placing the discs at increased risk in this position.

3.1.2 Evaluation While highly common in the general population, back pain can be a long-term disabling condition if not properly addressed. When evaluating this condition in gamers, a thoughtful and precise history and physical examination coupled with ergonomic assessment can provide sufficient clues to determine the etiology.

Mechanical Back Pain

Accounting for the majority of acute low back pain, mechanical pain refers to disruption in the inherent biodynamics of the anatomical components of the back.

3.1.2.1 History Taking The esports history taking does not stray far from traditional pain evaluations. In addition to onset, timing, provocative, and palliative components and associated symptoms, special attention should be made for any red flags of a more malignant etiology. Patients with weakness may not simply state, “I have hand weakness”, but express difficulty with buttons, mouse or controller grip, sluggishness with keyboard controls, or switching to new keybinds. The presence of numbness and tingling should always be further investigated to determine if symptoms fall in a specific peripheral nerve or dermatomal distribution.

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Back Pain Red Flags

Pain associated with weakness, gait difficulties, or bladder and bowel dysfunction should be causes for concern, and suggest a myelopathic origin. Weight loss and systemic symptoms such as fever may point towards underlying malignancy.

3.1.2.2 Physical Examination The esports examination should start with observation, both standing and seated. Examiners should pay special attention for any changes in spinal curvature or imbalances that may result from chronic maladaptive postures. Palpation may reveal hypertonic musculature, or active trigger points. Involved areas should be ranged both passively and actively to diagnose motion restrictions. A thorough neurological examination should be incorporated into any evaluation of complaints with potential spinal origin including manual muscle testing, sensation, reflexes, and gait. As with any other joint evaluation, the areas above and below should also be carefully investigated. For patients with neck pain, the shoulder should be evaluated for a referred pain origin. Similarly, the hip should be examined for patients with lower back complaints. If possible, visualization of the patient in their native gaming setup, either in real time or via photograph or teleconference, can reveal other imbalances. 3.1.2.3 Diagnostic Imaging A large majority of neck and back complaints in the esports athlete may be diagnosed based on history and physical examination alone [6]. If further diagnostic workup is required, simple X-ray is often the first modality. However, advanced imaging may be an appropriate subsequent step if the patient: 1. Presents with clinical signs of cord compression or myelopathy 2. Does not respond to conservative treatment 3. Has findings other than age-appropriate changes on X-ray

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Plain Radiography X-rays are often the first and only imaging necessary in most cases of back and neck pain. Spine radiographs should consist of an anterior-posterior and lateral view. Lateral views may reveal signs of chronic poor posture, such as straightened, worsened, or reversed normal curvatures. Flexion/extension views are usually only necessary if instability is suspected, and oblique views can be obtained to examine for spondylolysis. Magnetic Resonance Imaging While almost never the most appropriate first test, MRI can be the most informative. MRI can reveal disc herniations, degenerative disc disease, and evidence of radiculopathy. Contrast is usually only required when tumor or infection is suspected. While MRI may be beneficial in providing possible etiologies of symptoms, imaging may not correlate entirely with symptomatology. There is a very high incidence of positive findings on MRI in asymptomatic individuals. MRI results must be interpreted in conjunction with history and physical examination findings [6]. Computed Tomography (CT) Despite being one of the best imaging modalities to evaluate facet joint pathology, CT is not often utilized. The use of CT imaging in the gaming population should be reserved for patients who cannot undergo MRI. Electrodiagnostics Nerve conduction studies (NCS) and electromyography (EMG) can be helpful in cases of peripheral neuropathy and radiculopathy. NCS can distinguish between peripheral neuropathies and more central etiologies. EMG can be very helpful in picking up early signs of denervation and subclinical weakness. Screening EMG to include six upper limb muscles and the appropriate cervical paraspinal level can successfully diagnose 94–99% of cervical radiculopathies [7]. The downside of EMG is largely patient discomfort. NCS involves repetitive electrical shocks, and EMG is

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performed via needle evaluation, and can be poorly tolerated. The patient should be educated on the testing procedure when it is prescribed, and not upon arrival to the testing facility.

3.1.3 Treatment The exact treatment of a condition should obviously be reliant upon the underlying etiology. We will briefly discuss commonly employed treatment strategies across a majority of conditions, and expound on details in each specific pathology category.

3.1.3.1 Therapeutic Modalities Cold and heat therapy is often the first line employed by patients themselves, prior to presenting to the health care practitioner. Providing brief patient education on the effects of temperature on the inflammatory cascade can have long-lasting benefits. Cold therapy can reduce pain via vasoconstriction, decreased inflammation, and metabolic demand. Topical heat may facilitate pain relief by increased blood flow and elasticity of connective tissues [8]. The choice of temperature treatment is not set in stone. Generally, acute inflammatory processes are better influenced by cold, whereas chronic processes respond more appropriately to heat [9]. Nontraditional modalities such as acupuncture, yoga, and osteopathic manual therapy, may also be helpful. 3.1.3.2 Rehabilitation During periods of pain, the natural human tendency is to rest. However, for most cases, overt bed rest should be limited and attention should still be paid to stretching exercise and resumption of normal activities as soon as possible. Bed rest may lead to prolonged recovery times, and even worsening of symptoms. Once the acute pain phase has been completed, strengthening exercises may speed recovery. Even with the most motivated of populations, self-directed programs may not be as regular or effective as a formal course of physical therapy. Formal therapy

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programs may diagnose imbalances, provide further stabilization, improve flexibility, and promote proper posture. Transcutaneous electrical nerve stimulation (TENS) is a readily available device that delivers electrical impulses via surface electrodes. Studies have shown that TENS may be effective for chronic pain treatment when used in conjunction with more traditional modalities [10].

3.1.3.3 Pharmacological Management Use of over-the-counter (OTC) anti-inflammatory and analgesic medications can be widespread and pervasive in the athletic population. Given their readily accessible nature, the side effects of OTCs may not be widely known. Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen block the inflammatory cascade via inhibiting the activity of cyclooxygenase enzymes (COX 1 and/or 2). Long-term NSAID usage can have deleterious effects, such as gastrointestinal distress/damage and kidney dysfunction. NSAIDs may also interact with other medication metabolism. Prescription medications may be necessary for acute or chronic therapy. Anticonvulsants and antidepressants can be helpful for chronic pain and neuropathic symptoms. Opioids, powerful analgesic medications that can lead to tolerance, dependence, addiction, and death, may have utilization in cancer-related pain and other conditions, but will not be discussed. 3.1.3.4 Interventions While most cases of neck and back pain may be adequately treated with more conservative methods, more advanced methods may be necessary. Interventional spinal procedures, such as nerve blocks and corticosteroid injections, are performed using fluoroscopic guidance by highly trained physicians. Steroid injections are not recommended for long-term use due to the deleterious effects on healthy cartilage, bones, and tendons.

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Myofascial Conditions

Myofascial pain syndrome, Trigger points

3.2.1 Overview The initial presentation of musculoskeletal pain can be daunting, as it is associated with a broad differential. While a large number of cases may be due to underlying spinal abnormalities, myofascial pain has been shown to be the source of pain complaints in up to 30% of patients. Myofascial pain is characterized by taut bands in the muscle, called trigger points, that reproduce pain symptoms with palpation. It is a common and treatable cause of neck and back pain that can easily be addressed by most health care professionals. In the esports population, sedentary lifestyles and maladaptive postures may lead to an increased risk of myofascial conditions and at an earlier age than the non-gaming, age-matched population.

3.2.2 Pathogenesis Myofascial pain syndrome is a seemingly simple, yet remarkably complex disorder whose etiology is still actively debated. Despite this, there is a general literature consensus on certain aspects. The primary pain generator is a trigger point, a hypercontracted, palpable area of muscle that may be present in one or more places. Palpation of the site often results in pain in an anatomically separate location, which is classified as referred pain. While the precise pathophysiology of trigger points still remains unclear, it appears to be mediated by a central mechanism with an additional component of peripheral sensitization via the dorsal horn. Sustained sarcomere contracture leads to reduced blood flow and metabolic alterations, which in turn increases release of inflammatory mediators. Furthermore, in vivo studies

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have shown altered gluconeogenesis pathways in trigger points when compared to normal tissue as well as increased levels of lactate, suggesting the area itself is ischemic in nature [11, 12]. Development of trigger points may be preceded by seemingly trivial insults such as a minor muscle strain, long gaming session, adjustment of peripherals, sustained low-level contractions from chronic overuse, poor posture, or sleeping habits.

3.2.3 Presentation The presentation of a patient with myofascial pain syndrome may be indistinguishable initially from that of discogenic or radiculopathic origins. Pain is often acute in onset, and may or may not radiate. Patients may describe specific movements or positions that cause aggravation. Quality may vary from deep and achy to lightening or electric-like symptoms. For trigger points near midline, presentation may closely mimic that of facet syndrome. Occasionally, patients may state they can reproduce their symptoms with palpation, offering excellent diagnostic insight. Certain researchers further classify trigger points as “active” or “latent,” with the former producing spontaneous pain, the latter not. Both may elicit uncomfortable sensations with palpation [13]. Palpation may also elicit autonomic symptoms [14].

3.2.4 Diagnosis The diagnosis of myofascial pain is purely clinical, as there is no clear diagnostic testing. The most commonly utilized criteria to define trigger points was developed by Tough [15]. 1 . Tender spot in a taut band of skeletal muscle 2. Patient pain recognition 3. Predicted pain referral pattern 4. Local twitch response

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Physical examination findings of a normal motor and sensory exam coupled with a palpable nodule that reproduces symptoms suggests a component of myofascial pain. Provocative testing for radiculopathy and facet-mediated pain should be negative, such as neural tension tests.

3.2.5 Treatment Once the diagnosis of myofascial pain syndrome is made, equal attention should be paid to both resolution of pain symptoms and prevention of further recurrence.

3.2.5.1 Therapeutic Modalities Treatments like massage and stretching that are known to increase blood flow have been proposed to address the underlying microcirculation restriction. However, it is unclear if a regional increase in blood flow will affect the microcirculation of the trigger point. Manual therapeutic modalities have been shown to reduce pain associated with active trigger points. Of the proposed modalities, trigger point manual therapy, counterstrain, and muscle energy techniques may be the most promising. Trigger point manual therapy is performed by applying sustained digital pressure to the area of interest. The counterstrain and muscle energy techniques were first developed by osteopathic physicians, and utilize inherent muscle reflexes such as the muscle spindle and Golgi tendon reflex. 3.2.5.2 Pharmacological Management Analgesics, anti-inflammatories, and topical creams may provide symptomatic relief but do not adequately address the underlying pathophysiology. 3.2.5.3 Interventions Dry needling and trigger point injections have become widely acceptable forms of treatment. Needle-based treatments have been shown effective to release myofascial trigger points by eliciting a localized twitch response. A twitch response is a transient

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increase in muscle activity, and is considered to be a spinal reflex, as spinal cord transection between the brain and trigger point does not elicit a response. Relaxation after the twitch is thought to relieve capillary constriction, thus normalizing microcirculation [13]. Evidence has shown increased localized blood flow to trigger points after intervention [16]. Both injection techniques can be performed in office without specialized equipment, and are generally well-tolerated. When choosing between the two, it is important to note that dry needling was found to be as effective as using an injectable, but the latter resulted in less post-treatment soreness [17] Dry needling has been shown to result in sustained relief from pain for at least 6  weeks following intervention. Caution must be taken when treating the rhomboids, upper trapezius, and levator scapulae given the close proximity of lung tissue and risk of pneumothorax. Trigger point injections can be performed by appropriately trained health care providers, and are not limited to physician-­ only. Due to the efficacy and ease of treatment for this performance-­ declining condition, medical providers associated with esports teams are encouraged to pursue training. Other modalities, such as chemodenervation, electrical stimulation, cold laser therapy, and ultrasound therapy have been employed to treat myofascial pain with varying efficacy [13, 18].

3.3

Thoracic Outlet Syndrome

3.3.1 Overview Thoracic outlet syndrome is a condition in which either neural or vascular structures are compressed as they exit the thoracic outlet in the cervicothoracobrachial region. The majority of cases are neurological (95–99%); a small minority of cases involve compromise of either arterial or venous structures. Compression primarily occurs at one of three anatomical sites: the interscalene triangle, the costoclavicular triangle, and the subcoracoid or sub-pectoralis minor space. The interscalene triangle consists of the space between the anterior scalene muscle anteri-

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orly, the middle scalene muscle posteriorly, and the medial surface of the first rib inferiorly. The costoclavicular triangle is bound by the middle third of the clavicle anteriorly, the first rib posteromedially, and the upper border of the scapula posterolaterally. The subcoracoid space is bordered by the coracoid process superiorly, the pec minor anteriorly, and ribs 2–4 posteriorly. Less commonly, clavicular hypomobility or the presence of a cervical rib can cause compression of neurovascular structures.

3.3.2 Pathogenesis In the absence of structural alterations, such as a cervical rib, transversocostal or costocostal fibrous anomalies, abnormalities of the insertion of the scalene muscles, cervicodorsal scoliosis, or congenital uni- or bilateral elevated scapulae, thoracic outlet syndrome derives from acquired or functional discrepancies. In gaming, traumatic sources such as clavicle fracture, rib fracture, or whiplash/hyperextension neck injury are unlikely. Esports patients with thoracic outlet syndrome are more likely to develop the condition from repetitive stress injuries or postural factors resulting in closure of the three spaces outlined above. This closure can result directly from poor posture or from compensatory alterations to the muscles that border these spaces, such as scalene hypertrophy; decreased trapezius, levator scapulae, or rhomboid resting tong; or shortening of the scalenes, trapezius, levator scapulae, or pectoral muscles.

3.3.3 Presentation Symptoms depend on the portion of the plexus involved and the type of thoracic outlet syndrome: arterial, venous, or neurogenic. Generally, thoracic outlet syndrome does not follow dermatomal or myotomal distributions unless there is concomitant nerve root involvement.

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Patients with upper plexus involvement (C5–7) present with pain in the side of the neck, ear, and face that may radiate to the rhomboids and pectorals. Patients with lower plexus involvement (C8–T1) present with pain in the shoulder that radiates down the ulnar side of the forearm and into the fourth and fifth digits. With arterial thoracic outlet syndrome, patients demonstrate the “Ps and Cs”: pallor, paresthesias, pain, claudication, and cold intolerance. With venous thoracic outlet syndrome, patients report a feeling of heaviness and demonstrate edema and paresthesias. With neurogenic thoracic outlet syndrome, patients may demonstrate Raynaud’s phenomenon, but more commonly present with paresthesias, numbness, weakness, decreased fine motor skills, and occipital headaches.

3.3.4 Diagnosis Given the similarity of its clinical presentation to other conditions, any diagnosis of thoracic outlet syndrome must involve excluding other possible diagnoses. Electromyography and nerve conduction studies will usually show decreased ulnar sensorial but normal ulnar motor potentials with normal median sensorial potentials. Similarly, venography and arteriography can assist with the identification of venous and arterial thoracic outlet syndrome. At least two positive clinical tests are recommended for diagnosis via clinical testing only. Common thoracic outlet syndrome clinical tests are listed in Table 3.1 with their sensitivities, specificities, and likelihood ratios where available.

3.3.5 Treatment Conservative management including physical therapy should initially focus on symptom relief, followed by progression to exercises to address the tissues causing compression and limitation of

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Table 3.1  Reliability of thoracic outlet syndrome clinical tests [19] Test Roos Adson Wright Upper limb tension test

Sensitivity (%) 52–84 79 70–90 90

Specificity (%) 30–100 74–100 29–53 38

LR+ 1.2–5.2 3.29 1.27–1.49 1.5

LR0.4–0.53 0.28 0.34–0.57 0.3

motion. This may include joint mobilization, soft tissue mobilization, postural correction exercises, stretching of the muscles comprising the thoracic outlet, and strengthening of the muscles that stabilize the shoulder girdle and costoclavicular space. Studies are mixed with regard to the efficacy of botulinum injections to the anterior and middle scalenes. Some studies have found improvement in pain and spasm, while others have been inconclusive [20, 21]. In most cases, surgical intervention is not indicated unless conservative management has been ineffective, with the notable exception of cases of vascular thoracic outlet syndrome with limb-threatening complications.

3.4

Postural Dysfunctions

3.4.1 Forward Head Posture Nerd neck, iHunch

3.4.1.1 Overview Forward head posture refers to a pattern of upper thoracic and lower cervical flexion coupled with upper cervical and occipital extension. In and of itself, this posture is not necessarily pathologic and may be attributed to naturally occurring variations in craniovertebal or odontoid process angle. However, forward head posturing may also develop as a consequence of combined mus-

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cular weakness, muscular tightness, and abnormal spinal mobility [22]. When this exists in conjunction with pain or weakness, or when the curvature becomes more prominent over time, it is more likely to be a pathological variant. Both computer and console gamers are at an increased risk given their prolonged sedentary activities, and may have already begun to adopt this posture outside of gaming on presentation.

3.4.1.2 Pathogenesis In cases of accentuated thoracic kyphosis or lumbar lordosis, forward head posture may develop in a compensatory manner. However, it generally results from prolonged poor positioning. This may occur in sitting, standing, or lying. Any position where atlantoaxial extension and distal cervical flexion occur in conjunction can contribute to the development of this condition, including: 1. Mobile gaming 2. Texting posture maintained for long durations 3. Sleeping with elevated head 4. Slouched/slumped positioning With regard to gaming populations, this posture is particularly visible in common sitting positions for console players (e.g., Super Smash Bros. Melee). Longstanding maintenance of this posture results in alterations in muscle lengths and relationships. Functionally, semispinalis cervicis is weakened and lengthened while semispinalis capitis (bilateral action: cervical and atlantoaxial extension, unilateral action: contralateral head and neck rotation) is shortened and hyperactive. The longus cervicis or longus colli acts to limit lordosis as produced by the weight of the head and posterior cervical muscle contraction; in forward head posture, this muscle is shortened and tight. The longus capitis (bilateral action: flexion of cervical spine and head, unilateral action: ipsilateral lateral flexion and rotation of neck and head), however, is lengthened due to its insertion directly onto the occipital bone, rather than onto more distal points as for the longus cervicis.

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3.4.1.3 Presentation Forward head posture rarely exists in isolation. Given the interconnected nature of the spine, this particular condition is often found in conjunction with thoracic kyphosis and lumbar lordosis, which will be addressed in the next two sections of this chapter. Patients with forward head posture will demonstrate decreased overall cervical lordosis with compensatory extension at the atlanto-occipital joint. The head is subsequently shifted forward, hence the name. Patients with forward head posture may report a variety of symptoms, including • • • • • • • •

Increased pain and fatigue of neck and back muscles Decreased head and neck movement Tension headaches Jaw pain and inflammation Temperature changes in upper extremities Decreased arm and shoulder mobility Difficulty breathing Upper back/scapular pain

3.4.1.4 Diagnosis Diagnosis is purely clinical, with minimal utility of diagnostic measures like ultrasonographic assessment of neck flexor and extensor muscles. Any diagnosis of forward head posture should begin with observational postural analysis of the entire spine, given the interaction between the lumbar, thoracic, and cervical components. This assessment should be completed both in sitting, to assess patients in the positions assumed for gaming, and in standing, which is more sensitive to identification of forward head posture [23]. Traditionally employed by builders, a plumb line (a long string hanging from the ceiling with a weight attached to the end) can further aid diagnosis if available, as shown in Fig. 3.2. Ergonomic assessment of an individual’s setup should be conducted, as this is most often either the causative factor or aggravating factor.

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CENTER OF HEAD ANTERIOR TO SHOULDER JOINT CENTER OF THORAX

AT OR POSTERIOR TO HIP JOINT

ANTERIOR TO KNEE JOINT

ANTERIOR TO ANKLE JOINT

Fig. 3.2  An imaginary plumb line hanging directly down from the ceiling can be used to aid examination. When the body is in ideal posture, gravity should pass through specific joints and areas of the body, thus allowing for a more quantitative analysis

3.4.1.5 Treatment Optimal treatment of forward head posture must be multifactorial to successfully address both the causative factors and underlying pathology. Any intervention to address musculoskeletal deficits will inevitably fail if not coupled with environmental alterations to support improved posture, including improved workspace and sleep ergonomics.

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Table 3.2  Physical therapeutic interventions to target forward head posture Posture Mobility/ flexibility

Strength/ endurance

Cervical retraction Scapular retraction Cervical active/passive range of motion exercises Shoulder active/passive range of motion exercises Stretching of tight structures (most commonly trapezius, scalenes, sternocleidomastoid, pectoralis major/minor) Cervical self-SNAGs Cervical strengthening, progressing from isometric to isotonic Rhomboid/middle trapezius strengthening

Treatment of this condition is largely dependent on observed impairments, but will likely include the protocols listed in Table 3.2. Manual therapy should be used to complement active exercises, but must be partnered with education for patients on the role of exercise for long-term improvement. Soft tissue mobilization to tight structures, including the cervical extensors, trapezius, scalenes, sternocleidomastoid, and pectoralis major and minor muscles, can supplement stretching exercises. In particular, myofascial release and occipital release can improve tightness and pain. If intervertebral mobility is found to be lacking, central or unilateral posterior-anterior mobilization of the cervical spine may be appropriate. For patients with limited cervical rotation and facet joint mobility, sideglides, downglides, or SNAGs (sustained natural apophyseal glides) are appropriate. While research indicates that mobilization, thrust manipulation, and SNAGs all provide pain relief and improved mobility, they are not by themselves sufficient to resolve forward head posture [24]. Both cervical and thoracic mobilizations and thrust manipulations are correlated with short-term improvements in patients with mechanical neck pain. However, thoracic and cervical exercises supplemented with joint mobilizations are the most effective intervention for shortand long-term relief [25–27]. As with other myofascial conditions, electrical stimulation and thermal modalities may provide local, short-term pain relief but will not address underlying causes.

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3.4.2 Excessive Thoracic Kyphosis 3.4.2.1 Overview This overview is not designed to address structural issues of the thoracic spine, such as scoliosis, but rather excessive postural kyphosis deriving from a functional basis. This postural deficit is often associated with excessive cervical extension, or forward head posture, and can result from poor gaming ergonomics. 3.4.2.2 Pathogenesis Postural kyphosis is most commonly a function of sustained poor positioning, leading to tight chest wall muscles, including pectoralis major and minor; weakened/lengthened thoracic extensors and scapular retractors; and decreased thoracic intervertebral mobility [28]. Excessive kyphosis may act as a compensatory mechanism for other postural deficits. Facet arthropathy, spondylitic changes, and disc degeneration may also promote excessive kyphosis as a pain-relieving mechanism. 3.4.2.3 Presentation This condition is attributable to a pattern of weakness and tightness in the muscles of the chest and upper back. Patients will demonstrate a slumped or rounded upper back posture, often with scapular protraction and rounding of the shoulders as well. Patients often report feelings of fatigue, strain, or stiffness in the upper back. The mobility of the thoracic spine subsequently affects the mobility of the shoulders, particularly at the scapulothoracic joint. Any report of limited shoulder mobility or pain in the shoulders should prompt clinicians to examine the thoracic spine as well. 3.4.2.4 Diagnosis As with forward head posture, clinical examination is the primary means of identifying the underlying causes. Radiographic imaging may be useful to identify contributions from altered disc

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height, osteophyte formation, facet joint changes, or vertebral fractures. Of note, cervical spinal conditions commonly refer pain to the thoracic spine. As such, any examination for suspected thoracic pathology should also screen the cervical spine, particularly when the pain is located in the shoulder and scapular area.

3.4.2.5 Treatment Ergonomic assessment and modification is key to prevention and continued support of good posture. Limited research exists on the efficacy of spinal manipulation for thoracic musculoskeletal pain. Evidence does exist that spinal manipulation is associated with small, subclinical pain reductions and that multimodal care, including manual therapy, exercises, and education, is the most effective for pain reduction [29]. Research also suggests that changes in pain and mobility are greatest in patients who express positive perceptions of effect, further emphasizing the importance of education in clinical care. Exercises should address patient-specific impairments and may include those described in Table 3.3. Table 3.3  Physical therapeutic interventions to target excessive thoracic kyphosis Posture

Mobility/ flexibility

Strength/ endurance

Scapular retraction Scapular retraction with external rotation Rows Seated thoracic extension Stretching of tight structures (most commonly pec major and minor) Thoracic self-mobilization with foam roller Prone press-ups Thoracic rotation/“open book” stretches Facilitated/segmental breathing Rhomboid/middle trapezius Core Latissimus dorsi Serratus anterior

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3.4.3 Limited Lumbar Lordosis While excessive lumbar lordosis can promote compensatory thoracic kyphosis, decreased lordotic curve is more closely associated with low back pain.

3.4.3.1 Overview The mobility, stability, and positioning of the lumbar spine are all significantly impacted by the mobility, stability, and positioning of the hips, pelvis, and thoracic spine. In particular, limited hamstring flexibility has been found to correspond with limited lumbar lordosis and increased low back pain [30]. While limited data exist on posture within the gaming populations, analogous data from office workers who spend similar amounts of time sitting can provide a useful basis to draw conclusions about the role of posture in limiting lumbar lordosis and increasing risk for low back pain. Environmental Factors

In addition to musculoskeletal factors, low back pain is highly correlated with depression, anxiety, work stress, and similar psychosocial factors. Current best practice for nonspecific low back pain includes education and stress management techniques in addition to addressing relevant musculoskeletal factors [31].

3.4.3.2 Pathogenesis As with forward head posture and excessive thoracic kyphosis, alterations in normal lumbar spine lordosis seen in gaming populations are most commonly attributable to chronic sub-optimal postures. The lumbar spine, as with the thoracic and cervical spine, is supported by a variety of passive (vertebrae, discs, joints, ligaments) and active (global and local muscles) structures that act together to provide stability and mobility. Coordination between active and passive structures is required to maintain normal curvature. Discoordination can result from a number of

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sources, including acute trauma, chronic disuse of active support structures (decreased engagement of core muscles), and chronic malpositioning of passive support structures (sustained poor posture).

3.4.3.3 Presentation Patients with decreased lumbar lordosis may be largely asymptomatic. If pain is experienced, it is most often reported centralized over the lumbar spine, distributed across the pelvic brim, or in the muscles on either side of the lumbar spine. Patients may find relief in positions of increased hip and non-weight-bearing lumbar flexion. 3.4.3.4 Diagnosis As with all postural conditions, observational postural analysis is the first step to identification of this condition. Clinicians should consider a variety of differential diagnoses and be aware that excessive lumbar lordosis is as likely to be a symptom as it is a cause of low back pain. Radiographic imaging may be helpful to identify any structural changes. As with forward head posture and excessive thoracic kyphosis, decreased lumbar lordosis is often more of a functional than structural change. As such, clinical examination is the primary diagnostic tool for this particular postural impairment. 3.4.3.5 Treatment Ergonomic assessment and modification is key to prevention of injury and continued support of good posture. Environmental modification and education should be part of any treatment plan for a patient with a postural dysfunction. Depending on the primary cause, research suggests that conservative measures including physical therapy, cortisone injections, non-steroidal anti-inflammatory medications, and antidepressants are among the most effective treatments. Surgery is unlikely to be the best course of action barring serious structural concerns [31]. Treatment should emphasize continued mobility and avoidance of bedrest. A physical therapy plan to address low back pain

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Table 3.4  Physical therapeutic interventions to target limited lumbar lordosis Posture Mobility/flexibility

Strength/endurance

Repeated/sustained lumbar extension exercises Anterior pelvic tilts Hamstring stretching Hip internal/external rotation stretching Quadratus lumborum stretching ITB/TFL stretching Piriformis stretching Lumbar self-mobilization with foam roller Prone press-ups Hip flexors Gluteus maximus and medius Quadriceps Lumbar extensors Core girdle

from decreased lumbar lordosis should address components discussed in Table 3.4.

3.5

The Spine

3.5.1 Spondylosis Facet syndrome, Facet arthropathy, Degenerative Disc Disease

Spine

osteoarthritis,

3.5.1.1 Overview Spondylosis is a general term used to describe degenerative changes of the spinal column. With aging, degenerative bony changes are as commonplace and unavoidable as white hair or wrinkles, and may be of little clinical significance. However, due to predisposing factors, the gaming population may be at an increased risk for early degeneration and clinical complications.

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Spondylolysis

Spondylolysis is a vertebral defect of the pars interarticularis, most often observed at the L5 level. This is commonly seen in the pediatric population who engage in sports with hyperextension forces, like gymnastics.

3.5.1.2 Pathogenesis Age-related wear and tear is a natural process of aging as cartilage wears away and intervertebral discs dessicate. This process may be accelerated by repetitive trauma, poor posture, abnormal spinal curvatures, or any process that places increased levels of stress on the spine. While the facet joints and discs may be anatomically separate, they have a corollary biomechanical relationship. Degenerative Cascade Repetitive microtrauma to the intervertebral disc results in circumferential outer annular tears. This subsequently interrupts blood flow to the disc, further undermining the structural integrity. Circumferential tears then coalesce into radial tears, which affect the underlying nucleus pulposus. A biologically incompetent disc places increased loads on the neighboring facet joints, accelerating degeneration and resulting in synovitis. Facet joint irritation leads to abnormal motion, as well as hypertonicity of the surrounding muscles. Thinning of the intervertebral disc from cumulative stress and annular tears reduces the shock-absorbing properties, placing more load on the facet joints. This cascade then continues, as dysfunctional motion leads to further microtrauma, synovial hypertrophy, and increased capsular laxity [32]. In response to joint instability and the subsequent pathological motion, the body responds by laying down additional bone in areas of increased stress, such as the vertebral endplates and facet joints. The result of this process is spondylosis and can affect the vertebral bodies, facet joints, and neural foramina. Degenerative disc disease often accompanies spondylosis, and it can be difficult to separate the two entities.

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Additional articulations in the lower cervical spine, called the uncovertebral joints, or joints of Luschka, are predisposed to osteoarthritis. Degeneration at these locations can further narrow corresponding intervertebral foramina. Thus, the most common locations of the cervical spine that exhibit degenerative changes are between C4–C7. In the lumbar spine, L4–5 and L5–S1 are the most commonly affected facet joints. Posture and Degeneration The direct role of abnormal posture on degeneration is hotly debated. Any provider who has been involved in the low back pain treatment process knows it is not only complicated, but often multifactorial. Certain biomechanical correlates have been associated with low back pain with sitting, including intradiscal pressure, segmental loading, and segmental flexion. Intradiscal measurements have shown increased pressures during sitting when compared to standing, and a further increase in pressure with poor posture. Similarly, increases in segmental loading and flexion have been shown with sitting [33]. Furthermore, studies on neck pain have shown that forward head posture has been shown to lead to degenerative changes in the cervical spine. The mechanism is thought to be secondary to excessive stretching of the capsular ligaments, resulting in decreased threshold of nerve endings and altering proprioception. Regardless, scientific research states posture has a role in back health, and should be thoroughly evaluated and treated like any other contributing factor. Console gamers may theoretically be at an increased risk, as simple observational inferences reveal increased lumbar flexion when compared to PC gamers.

3.5.1.3 Presentation As spondylosis is a general condition, symptoms can manifest from a variety of etiologies. Pains may be primarily facetogenic, or arise when pressure is begun to be placed on the spinal cord (spinal stenosis) or nerve roots (radiculopathy). When symptoms are facetogenic, patients may complain of neck or back stiffness. Symptoms are usually worse in the morn-

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ing and during activity. Facet pain may manifest locally, or be referred. Patients may be able to pinpoint specific locations, often posterolateral to the spinous processes, and use terms such as “deep” and “achy.” However, spondylotic pain may be difficult to localize. Patients may also complain of referred pain, depending on location. If the cervical spine is affected, symptoms may refer to the shoulder, proximal limb, or occiput. Facet-mediated pain typically does not radiate past the shoulder, and is aggravated by rotation or flexion. C1–2 and C2–C3 levels can refer rostrally to the occiput, so patients may commonly present with unilateral headaches. Cervicogenic Headaches

Cervicogenic headaches can result from a multitude of underlying spinal pathologies, including spondylosis. They are typically unilateral, and radiate from the posterior occiput in a “ram’s horn” pattern. Patients with lumbar facet pain may present with referred hip pain or leg pain. Pain that radiates passed the knee or elbow suggests another etiology besides facet-mediated pain, such as radiculopathy [34]. Spondylosis resulting in radiculopathy often results in primarily radiating, appendicular pain [35]. These etiologies will be discussed at length in future sections. Facet Syndrome Versus Radiculopathy

Unlike radiculopathy, radiating pain from facet syndrome does not follow a dermatomal pattern.

3.5.1.4 Diagnosis Physical Examination One of the most frequent findings on physical examination is decreased range of motion of the spine. This is most pronounced

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in extension, where facet loading is at its highest. Lateral bending may also be affected, whereas neck rotation may be spared, as cervical rotation is a predominant function of the upper cervical spine. In addition to stiffness resulting from pathological spinal segments, surrounding paraspinal musculature tightens and becomes hypertonic. As the disease progresses, osteophytes may proliferate, further limiting segmental motion. Extension of the corresponding spinal region may be limited if facets are involved, and may result in pain. Facet joints can be palpated and may be tender. In the cervical spine, they lie approximately 1 in. lateral to the spinous processes. It is important for the overlying muscles to be relaxed, as tightened overlying musculature may make palpation difficult. Patients may be placed in the prone position for best results. Similarly, overlying paraspinal muscles can be felt for hypertonicity, tenderness, and spasm. The cervical compression test is a nonspecific test for cervical spondylosis. To perform, the examiner first laterally flexes the patient’s head before providing an axial load. Ipsilateral neck pain indicates a positive result. In the lumbar spine, the lumbar facet loading test is performed by placing the lumbar spine in extension and ipsilateral rotation. This motion increases forces on the posterior facet joints, and may reproduce facetogenic symptoms. Lhermitte’s sign, a test classically employed for multiple sclerosis, is also a nonspecific test for cervical spondylosis. The test is considered positive if a feeling of electrical shock is felt down the spine with rapid passive neck flexion. A positive test suggests an underlying cervical spine process. Imaging Most patients with spondylosis do not require further investigation than a careful history and physical examination. There is no specific imaging study for facet-mediated pain. When imaging is performed, it should be used only in careful conjunction with gathered information, as spondylotic changes can be present in asymptomatic individuals. While X-ray or MRI may reveal degenerative changes, this is not diagnostic. Depending on the age

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of the patient, correlation between imaging and clinical symptoms is poor. For older patients, degenerative changes of the spine may be normal findings. However, in the younger, gaming population early arthritis should be considered abnormal. Disc degeneration can be seen in greater than half of adults in their 30s, and may not correlate with symptoms. X-ray imaging can aid in diagnosis, and may reveal loss of disc height, osteophyte formation, facet joint changes, and subsequent foraminal narrowing. The radiographic presence of spondylosis in a young gamer should be considered abnormal.

3.5.1.5 Treatment Conservative treatment is the mainstay of spondylosis treatment. While no amount of stretching or physical therapy can reverse degenerative changes, it can prevent progression and alleviate symptoms. Patients should first be educated on proper ergonomics and lifestyle modifications. For cervical spondylosis, special attention should be paid to desk and monitor heights. For primarily lumbar complaints, attention should be paid to what type of chair is being used, and the dimensions. Further guidelines can be provided in the ergonomics chapter (Chap. 5). For patients with acute pain, treatment should first be focused on pain control before progressing to stabilization and restoration of function of the affected spine. Therapeutic Modalities Heat and cold treatments are commonly employed by patients. Superficial cryotherapy induced vasoconstriction, thus decreasing the presence of inflammatory mediators, and subsequently pain. Cervical orthoses, such as soft collars, have a limited role and should be avoided long term. Physical therapy can be effective for restoring range of motion, and may incorporate decompressive therapies such as traction. Therapy may focus on postural modification, proprioception, core strengthening, and flexibility. In general, extension-based protocols should be avoided to avoid further aggravation of the facet joint. For patients with lumbar complaints, hamstring flexibility is

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paramount as tightness can accentuate lumbar lordosis. Similarly, osteopathic manual medicine may be helpful [36]. Pharmacologic Management Over-the-counter NSAIDs may provide analgesic and anti-­ inflammatory relief by helping quell the underlying inflammatory process and lessen spondylosis-related neck and back pain. If patients complain of muscle spasms, muscle relaxants may be clinically appropriate. Interventions Interventions targeting the facet joint can often provide lasting pain relief, and avoid the systemic consequences of oral medications. Fluoroscopic-guided corticosteroid injections Nociceptive input to the zygapophyseal joint is provided via the medial branches of corresponding spinal segments, and can be blocked via multiple interventions. Longer-lasting medial branch neurotomy is performed via radiofrequency ablation (RFA). For those who do not respond to RFA, decompressive surgery or fusion may be necessary.

3.5.2 Intervertebral Disc Disease Discogenic pain, degenerative disc disease

3.5.2.1 Overview Disc disease is a pathological process that results in anatomical changes in the intervertebral discs. This most commonly results from degeneration, trauma, or a combination of both. Intervertebral (IV) discs serve a vital role in back health, and loss of disc integrity can have a drastic effect on the surrounding structures including the facet joints, spinal nerves, and the spinal cord itself. Disc disease can be further classified into degenerative disc disease, disc disruption, and disc herniation [37].

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3.5.2.2 Pathogenesis Disc disease is unlikely to arise from one specific cause, but rather a build-up of multiple microtraumas. Over time, small factors contribute to discal degeneration, which then predisposes that level to further injury, such as disruptions and herniations. The IV disc has two components: the gelatinous inner nucleus pulposus and tough outer annulus. The primary function of the IV disc is to relieve pressure on the vertebral bodies. Subsequently, excessive loads can lead to disc damage via increased and nonoptimal pressure. Intradiscal pressure is influenced by posture, though the effect on back pain is still debated. Lumbar disc pressures are lowest when supine, and highest when seated with forward flexion and some degree of weight bearing [38–40]. Furthermore, with the spine in neutral or extension, the facet joints offer some degree of movement guidance. However, when the spine is in flexion, facets offer very little resistance, placing further pressure on the IV discs. Disc disease usually begins with small annular tears that coalesce over time. Disc degeneration may begin insidiously from small microtraumas, but as tears compound, the fluidity of the nucleus pulposus and the integrity of the annulus is compromised. As the internal architecture of the disc degrades, there may be a noticeable loss of disc height, which leads to instability and propensity for further injury. Forward flexion places anterior pressure on the disc and results in posterior nucleus pulposus displacement. Excessive anterior loads may result in prolapse of the inner nucleus pulposus through the annular fibers [41, 42]. Trauma, usually a result of improper lifting techniques, can also lead to prolapse of the inner nucleus pulposus. Herniated disc material can have further clinical consequences via compression of the spinal cord or spinal nerves. Types of Disc Disease

Disc disruption refers to degeneration of the internal disc architecture with little or no noticeable external deformation. This can lead to disc herniation, which is extrusion of disc material outside of its anatomical region.

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Disc herniations most commonly occur at C5–6, L4–5, and L5–S1. Disc herniations can be classified according to their location as either posterolateral, lateral, or central. Depending on the location of the herniation, radiculopathy may result for either direct mechanical pressure or the corresponding inflammatory response. Posterolateral/paramedian disc herniations are the most common in the lumbar spine, as the lateral fibers of the posterior longitudinal ligament are the thinnest. As the spinal nerve of that corresponding level has already exited the spinal column, posterolateral disc herniations can result in compression of traversing, lower spinal nerves. Central disc herniations result from posterior pressure, possibly compressing the spinal cord itself, resulting in myelopathy or cauda equina past the conus medullaris.

3.5.2.3 Presentation Disc disease often results in pain which may be acute or chronic. Acute pain is often accompanied by a history of lifting, twisting, bending, or coughing that may or may not correspond with a sensation of “popping.” However, many cases of disc herniation are spontaneous and may not have a noticeable origin. Symptoms are often worsened by holding the neck in one position for long periods of time, such as driving or gaming. For esports athletes that may have organizational backing including personal trainers, disc herniations may be more common at the beginning of the season when they transition from little physical activity to formal training. Discogenic pain alone is usually axial. If disc damage results in hernations that compress spinal nerves, axial pain is accompanied by radicular symptoms of the corresponding nerve level, which is discussed later in the chapter. Symptoms are aggravated by movements that place pressure on the disc, such as forward flexion or Valsalva.

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3.5.2.4 Diagnosis Physical Examination When discogenic pain is suspected, a thorough neurological examination can often diagnose the exact level of injury, without requiring advanced imaging. The area of maximal pain should be inspected. Overlying musculature may be hypertonic or spasmodic. Palpation of the region around the spinous process may elicit pain. Range of motion may also be limited secondary to pain, most commonly in flexion. If symptoms are solely discogenic, patients should not have radicular symptoms. Strength and sensory examination can reveal if there is any spinal nerve involvement, as well as reflex testing. Large central disc herniations can result in signs of myelopathy, indicating an urgent workup is necessary. Imaging Imaging may be included in the initial examination if there are signs of neurological compromise. Simple X-rays may reveal decreased disc height, foraminal narrowing, and facet arthrosis. MRI findings can be supportive of the diagnosis, but should only be used in careful conjunction with the history and physical examination. Disc degeneration can be found in up to a large majority of asymptomatic individual MRI images [43]. Certain MRI findings, such as annular fissures and Schmorl’s nodes, have been found to be of unclear clinical significance. Annular fissures, or tears, have been found to have no correlation with back pain in multiple studies. Schmorl’s nodes represent nucleus pulposus herniations and are related to degenerative changes, but have been found to not be an independent risk factor for back pain [44]. Modic changes (endplate degeneration) may also be seen on MRI and are related to degenerative disc disease, but their clinical significance remains unknown.

3.5.2.5 Treatment Multiple studies have shown that disc protrusions and extrusions spontaneously resolve without surgical treatment [45]. However,

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pain may be acute and interfere with activities of daily living, and therefore impede recovery. The goal of nonsurgical treatment should be to reduce disc irritation and return the patient to their prior level of functioning. Complete, prolonged bed rest should never be recommended, and patients should be encouraged to continue pain-free activities [46]. Therapeutic Modalities Exercise has been associated with positive outcomes in the treatment of low back pain and should be initiated once pain is tolerable. In addition to back and core strengthening, motor retraining may be necessary. Specific types of exercise is patient-specific, depending on the type and location of disc herniation, and should be individually tailored. Lumbar stabilization may address training of the small muscles of the spine, such as the multifidi. Aquatic therapy has various benefits related to the properties of water itself. Pool-based therapy reduces gravitational stress on the body and increases buoyancy. Water can also decrease stress via the gate theory from the direct sensory input. Studies have also found manual therapy via spinal manipulation to be more effective than placebo [47]. Pharmacological Management There is no clear consensus regarding the exact agents and duration of pharmacological management. NSAIDs use is common in the back pain population, and may have been consumed extensively prior to presentation to the health care practitioner. The role of muscle relaxants also remains controversial, and should be reserved for patients with pain that affects sleep. Topical treatments, such as diclofenac gel and lidoderm patches, may not penetrate deep enough to be truly effective, but have minimal side effects when compared to the oral formulations. For patients with severe cervical radicular pain, a short course of oral glucocorticoid therapy may be warranted. However, the data is limited [48].

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Interventions Spinal procedures, such as epidural steroid injections, have become the bread and butter of interventional spine practices. By injecting anesthetic and corticosteroid into the anterior epidural space, the posterolateral intervertebral disc is bathed in medication, and may reduce pain. However, the efficacy of epidural steroid injection for discogenic pain has not been studied to satisfaction [49, 50]. Intradiscal electrothermography annuloplasty has not been shown to be an effective form of treatment. Intradiscal treatments, such as electrothermal therapy and percutaneous disc compression, are less invasive than surgical options, and may be effective in relieving cervical radicular pain caused by intervertebral disc protrusions. Surgical options may be pursued for patients with persistent pain after conservative options have been fully explored, but the literature lacks a clear consensus [51].

3.5.3 Radiculopathy 3.5.3.1 Overview Radiculopathy is a pathologic process affecting a spinal nerve root resulting in physiologic dysfunction. Symptoms resulting from spinal nerve root irritation or damage are referred to as radicular pain, and can produce a multitude of other symptoms in that specific nerve’s dermatome and myotome. 3.5.3.2 Pathogenesis Spinal nerve roots are the fundamental connection between the central and peripheral nervous system. Small rootlets leave the spinal cord, and converge into common trunks. They then traverse the spinal canal before exiting the intervertebral foramina. Because of anatomical differences in structure and vascularity, spinal nerve roots are inherently less resilient than peripheral nerves [52].

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Nerve root damage may arise from a multitude of causes, the two major etiologies being direct mechanical pressure or chemical irritation. Direct pressure can result from spondylotic changes or disc herniation. In the cervical spine, root injury is most commonly caused by intervertebral disc herniations, followed by spondylitis changes, including degenerative changes at the uncovertebral joint. Disc herniations can lead to radiculopathy either via mechanical compression or via an inflammatory response. Disc herniation is a very common cause of radiculopathy, even if imaging findings reveal no direct mechanical compression. The nucleus pulposus is usually sequestered inside the annular fibers. When exposed to the body’s environment, it becomes highly antigenic, and stimulates an autoimmune inflammatory cascade. This causes swelling and dysfunction of the neighboring spinal nerves. Similarly, direct mechanical compression compromises the vascularity, inducing local ischemia and subsequently setting off an inflammatory cascade.

3.5.3.3 Presentation Radicular pain differs from that of facet and discogenic origins in that limb pain may be more prominent than axial pain. Axial pain may only be a secondary issue, or absent entirely. Patients often present with pain, numbness, tingling, or weakness in the distribution of the affected nerve root. Differentials of Radiculopathy

Radiculopathy resulting from disc herniation is often acute in onset, with patients able to pinpoint the symptom onset. Spondylotis-­related radiculopathy is often more insidious in the onset.

Symptoms resulting from radicular pain depend on the level of the spinal nerve root involved. For lumbosacral involvement, over 90% are L5 and S1 radiculopathies. Patients may also present

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with sensory loss, weakness, and reflex changes in the specific nerve distribution. Patients may also present with the diagnosis of sciatica, a nonspecific term used to describe a variety of conditions in which the primary complaint is burning pain running in the general sciatic nerve distribution. Sciatica

Most sciatica diagnoses can be credited to L5 or S1 radiculopathy rather than piriformis syndrome or other direct injuries to the sciatic nerve.

3.5.3.4 Diagnosis Physical Examination A diagnosis of radiculopathy is suspected if history taking reveals radiating appendicular pain that crosses more than two joints. A careful neurological evaluation may reveal subclinical abnormalities. Sensory evaluation may show specific dermatomal ­delineations, shown in Fig. 3.3. Localized muscle weakness may be elicited via manual muscle testing. Long-standing radiculopathy may result in muscle wasting of the corresponding myotome that is visible to the naked eye. Severe muscle weakness is unlikely related to a single nerve root pathology, and points towards another, more distal etiology. When lumbar radiculopathy is suspected, gait evaluation, including heel and toe walking, may show side-to-side differences. Single leg calf raises can also determine side-to-side differences in calf strength. Key reflexes, muscles, and their corresponding dermatomes are listed in Tables 3.5 and 3.6. Root Tension Signs

After a neurological evaluation has been performed, specific provocative tests that place the nerve under traction offer further evidence [53]. By placing the spinal nerves under traction, symptoms attributed to radiculopathy may be reproduced.

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Fig. 3.3  Spinal dermatome map

Upper Limb Tension Test

The upper limb tension test (Elvey’s Test) can aid in diagnosis of cervical radiculopathy. To perform the test, in a seated position, the patient’s head is rotated contralaterally while the ipsilateral arm is abducted with the elbow in full extension. Symptom reproduction is considered a positive test. Straight Leg Raise Test

Lumbar radiculopathy can be investigated using the straight leg raise (SLR) or slump test. The straight leg raise test, also known

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Table 3.5  Cervical nerve roots and their corresponding dermatomes, key muscles, and associated reflexes Root level C5 C6 C7 C8 T1

Dermatome Shoulder, lateral arm Lateral forearm, thumb, and index finger Middle finger 4th and 5th digits Medial forearm

Key muscles Deltoid Biceps

Reflexes Supinator Biceps

Triceps Finger abduction Intrinsic hand muscles

Triceps None None

Table 3.6  Lumbar nerve roots and their corresponding dermatomes, key muscles, and associated reflexes Root level L1 L2 L3 L4 L5 S1

Dermatome Greater trochanter, groin Front of thigh Front of thigh, medial lower leg Inner buttock, dorsum of foot, big toe Back of thigh, lateral leg, dorsum of foot Buttock, back of thigh

Key muscles None Psoas Quadriceps Tibialis anterior EHL

Reflexes None None Knee jerk Weak knee jerk Hamstring

Calf

Ankle jerk

as Lasegue’s test, has various protocols. In general, the test is performed with the patient in the supine position. The examiner flexes the patient’s hip by lifting the affected leg from the table with the foot held in dorsiflexion. Reproduction of radiating symptoms is considered a positive test, and usually occurs when hip flexion is between 30° and 60°. A second, verification step, may be taken by flexing the knee. A bowstring sign refers to pain relief with a flexed knee during a positive straight leg raise test. The SLR test places the lumbosacral nerve roots under dural tension, and is most helpful for L5 and S1 radiculopathies [54].

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Hamstring Tightness

Hamstring tightness is highly prevalent in the gaming population, and can lead to falsely positive SLR testing. Pain and tightness in the distribution of the hamstrings is not considered a positive test.

Slump Test

The slump test can offer further confirmation, and be helpful for patients who may not be able to assume the supine position. The seated patient is asked to slump forward with poor posture while the examiner extends the knee. Radiating pain down the sciatic nerve distribution is considered positive. Reverse Straight Leg Test

Also known as the femoral nerve stretch test or Ely’s test, this test is performed with the patient in the prone position and the examiner on the patient’s affected side. The examiner then extends the hip with the knee held in 90 degrees of flexion. The test is considered positive if anterior thigh pain is felt, or symptoms are reproduced, and is suggestive of femoral nerve or L2–4 root involvement. Spurling’s Test

The traditional Spurling maneuver is formed by keeping the head in neutral and applying axial pressure from the top of the head down the cervical spine. However, the modified Spurling’s maneuver (usually also referred to as “Spurling’s maneuver”) is more commonly employed. The patient is placed in cervical extension, and ipsilateral rotation and lateral bending. Axial pressure is then added. The test is considered positive if symptoms are reproduced and travel past the shoulder. Localized neck pain on testing is not considered positive. While the sensitivity of modified Spurling’s is high, the sensitivity is unreliable. Thus, a negative test does not rule out cervical radiculopathy.

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Distraction Tests Shoulder Abduction Relief Sign

In a sitting position, the patient’s ipsilateral humerus is abducted. Alleviation of radicular pain is considered positive. Manual Neck Distraction Test

The manual neck distraction test is performed by applying superior traction at the base of the occiput and jaw. The test is considered positive if symptoms decrease. Imaging For the majority of atraumatic neck and back pain, imaging is not necessary. A 2009 meta-analysis compared immediate imaging with usual care for patients with acute to subacute back pain, and found no difference in long-term outcomes between the two groups [55]. X-Ray

If conservative treatment is ineffective, or patients describe pain affecting their ability to perform their activities of daily living or occupation, imaging may be pursued. In most cases, X-ray of the spine should be the first imaging study performed to evaluate radicular pain. Images may reveal degenerative changes of the spine, or facet narrowing. Spine radiographs should consist of an anterior-posterior and lateral view. Lateral views may reveal signs of chronic poor posture, such as straightened, worsened, or reversed normal curvatures. Flexion/extension views are usually only necessary if instability is suspected. Magnetic Resonance Imaging

MRI is usually only necessary if the patient is not responsive to conservative treatment, if there is progression of symptoms, or X-ray reveals findings other than age-appropriate changes. MRI may be considered prior to X-ray if there are physical exam findings suggestive of cord compression or myelopathy. If MRI is contraindicated, CT myelography may be a suitable alternative.

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Electrodiagnostics

Electrodiagnostic tests such as nerve conduction studies and electromyography can be used to distinguish cervical radicular pain from peripheral nerve entrapment or neuropathy. Screening EMG that includes six upper limb muscles and corresponding cervical paraspinal levels can identify 94–99% of cervical radiculopathies [7].

3.5.3.5 Treatment Radiculopathy can often be extremely painful, and treatment should focus on symptomatic relief and resumption of ADLs. After acute pain has resolved, attention should be paid to find the underlying cause. Radiculopathy in the young population that is not related to improper lifting mechanics should always be considered abnormal. Due to poor posturing, the gaming population may be at an increased risk for spondylosis, disc degeneration, and subsequent radiculopathy. Prevention of future occurrences should be the final treatment step. Therapeutic Modalities Thermotherapy and cold therapy may be used to modulate pain. Deep heating modalities (ultrasound) are best avoided in the case of radiculopathy as this may increase inflammation and further aggravate the nerve root. TENS can assist in pain modulation, thus allowing patients to participate in more aggressive forms of therapy. TENS has been shown to be useful in certain instances of low back pain, and is believed to act via the gate theory. By stimulating large fibers, this blocks nociceptive input. Cervical traction, application of a distracting force to the neck is commonly used for cervical radiculopathy, but lacks proven efficacy [56]. Patient education should be focused on assisting the patient in finding optimal pain-free positioning. Physical activity should be resumed as early as possible. Physical therapy can be beneficial for not only pain resolution but prevention of further recurrences. Spinal biomechanics can be

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restored via diagnosis and treatment of range-of-motion deficits, and emphasis on strengthening and stabilization of related muscles. Pharmacological Management Oral NSAIDs are considered first-line pharmacological management for cervical radiculopathy. The clinical indications for lumbosacral involvement is less clear, as there is little evidence to suggest that NSAIDs are more effective to placebo in patients with sciatic distribution pain [57]. Adjunct medications may include muscle relaxants, tricyclic antidepressants, and antiepileptics. Muscle relaxants are best used in the acute period and at night due to their sedating side effects. Gabapentin is also commonly employed for the treatment of radicular pain. Gabapentin is best started at night due to sedating side effects, and gradually titrated up as tolerated. Pregabalin may also be used for those who do not tolerate gabapentin or hepatic or renal impairments [55]. Tricyclic antidepressants and SSRIs may also provide more long-­ term control of pain [58]. Interventions Epidural steroid injections decrease inflammation through corticosteroid injection of nerve roots. The nerve root is bathed in corticosteroid solution in the epidural space. These treatments are effective for symptom management, and should be used only in combination with active rehabilitation [59]. The Spine Patient Outcome Research Trial found that surgery was favorable over nonoperative treatment in patients with lumbar radicular symptoms caused by disc herniation [60]. While surgery may lead to faster resolution of symptoms, long-term functional outcomes are similar to nonsurgical treatment options. Surgical intervention has not shown to have greater outcomes when compared with conservative measures. Surgical evaluation is considered prior to conservative management when there is evidence of progressive neurologic deficits [61].

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meta-analysis. J Manip Physiol Ther. 2018;41(6):530–9. https://doi. org/10.1016/j.jmpt.2018.02.002. 27. Cho J, Lee E, Lee S.  Upper thoracic spine mobilization and mobility exercise versus upper cervical spine mobilization and stabilization exercise in individuals with forward head posture: a randomized clinical trial. BMC Musculoskelet Disord. 2017;18(1):525. https://doi.org/10.1186/ s12891-­017-­1889-­2. 28. Sahrmann S. Movement system impairment syndromes of the extremities, cervical and thoracic spines. New York: Elsevier Health Sciences; 2010. 29. Southerst D, Marchand AA, Côté P, Shearer HM, Wong JJ, Varatharajan S, et al. The effectiveness of noninvasive interventions for musculoskeletal thoracic spine and chest wall pain: a systematic review by the Ontario Protocol for Traffic Injury Management (OPTIMa) collaboration. J Manip Physiol Ther. 2015;38(7):521–31. https://doi.org/10.1016/j. jmpt.2015.06.001. 30. Sadler SG, Spink MJ, Ho A, De Jonge XJ, Chuter VH. Restriction in lateral bending range of motion, lumbar lordosis, and hamstring flexibility predicts the development of low back pain: a systematic review of prospective cohort studies. BMC Musculoskelet Disord. 2017;18(1):179. https://doi.org/10.1186/s12891-­017-­1534-­0 31. Delitto A, George S, Van Dillen L, Whitman JM, Sowa G, Shekelle P, et  al. Low back pain: clinical practice guidelines linked to the international classification of functioning, disability, and health from the orthopaedic section of the American Physical Therapy Association. J Orthop Sports Phys Ther. 2012;42(4):A1–A57. https://doi.org/10.2519/ jospt.2012.42.4.A1 32. Kalichman L, Hunter DJ.  Lumbar facet joint osteoarthritis: a review. Semin Arthritis Rheum. 2007;37(2):69–80. https://doi.org/10.1016/j. semarthrit.2007.01.007. 33. Hedman TP, Fernie GR.  Mechanical response of the lumbar spine to seated postural loads. Spine. 1997;22(7):734–43. https://doi. org/10.1097/00007632-­199704010-­00004. 34. Schwarzer AC, Wang SC, Bogduk N, McNaught PJ, Laurent R. Prevalence and clinical features of lumbar zygapophysial joint pain: a study in an Australian population with chronic low back pain. Ann Rheum Dis. 1995;54:100–6. https://doi.org/10.1136/ard.54.2.100. 35. Binder A.  Cervical spondylosis and neck pain. Br Med J. 2007;334(7593):527–31. https://doi.org/10.1136/bmj.39127.608299.80. 36. Bronfort G, Haas M, Evans RL, Bouter LM. Efficacy of spinal manipulation and mobilization for low back pain and neck pain: a systematic review and best evidence synthesis. Spine J. 2004;4:335–56. https://doi. org/10.1016/j.spinee.2003.06.002. 37. Fardon DF, Williams AL, Dohring EJ, Murtagh FR, Gabriel Rothman SL, Sze GK. Lumbar disc nomenclature: version 2.0: recommendations

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of the combined task forces of the North American Spine Society, the American Society of Spine Radiology, and the American Society of Neuroradiology. Spine. 2014;39(24):E1448–65. https://doi.org/10.1097/ BRS.0b013e3182a8866d. 38. Wilke HJ, Neef P, Caimi M, Hoogland T, Claes LE.  New in  vivo measurements of pressures in the intervertebral disc in daily life. Spine. 1999;24(8):755–62. https://doi.org/10.1097/00007632-­ 199904150-­00005. 39. Claus A, Hides J, Moseley GL, Hodges P. Sitting versus standing: does the intradiscal pressure cause disc degeneration or low back pain? J Electromyogr Kinesiol. 2008;18(4):550–8. https://doi.org/10.1016/j.jelekin.2006.10.011. 40. Bogduk N, Windsor M, Inglis A. The innervation of the cervical intervertebral discs. Spine. 1988;13(1):2–8. https://doi.org/10.1097/00007632-­ 198801000-­00002. 41. Choi YS.  Pathophysiology of degenerative disc disease. Asian Spine J. 2009;3(1):39–44. https://doi.org/10.4184/asj.2009.3.1.39. 42. Munter FM, Wasserman BA, Wu HM, Yousem DM. Serial MR imaging of annular tears in lumbar intervertebral disks. AJNR Am J Neuroradiol. 2002;23(7):1105–9. 43. Jarvik JJ, Hollingworth W, Heagerty P, Haynor DR, Deyo RA.  The Longitudinal Assessment of Imaging and Disability of the Back (LAIDBack) Study: baseline data. Spine. 2001;26(10):1158–66. https:// doi.org/10.1097/00007632-­200105150-­00014. 44. Yin R, Lord EL, Cohen JR, Buser Z, Lao L, Zhong G, et al. Distribution of Schmorl nodes in the lumbar spine and their relationship with lumbar disk degeneration and range of motion. Spine. 2015;40(1):E49–53. https://doi.org/10.1097/BRS.0000000000000658. 45. Saal JS, Saal JA, Yurth EF. Nonoperative management of herniated cervical intervertebral disc with radiculopathy. Spine. 1996;21(16):1877–83. https://doi.org/10.1097/00007632-­199608150-­00008. 46. Hagen KB, Hilde G, Jamtvedt G, Winnem M. Bed rest for acute low-back pain and sciatica. Cochrane Database Syst Rev. 2004;4:CD001254. https://doi.org/10.1002/14651858.CD001254.pub2. 47. Assendelft WJ, Morton SC, Yu EI, Suttorp MJ, Shekelle PG.  Spinal manipulative therapy for low back pain. Cochrane Database Syst Rev. 2004;1:CD000447. https://doi.org/10.1002/14651858.CD000447.pub2. 48. Ghasemi M, Masaeli A, Rezvani M, Shaygannejad V, Golabchi K, Norouzi R. Oral prednisolone in the treatment of cervical radiculopathy: a randomized placebo controlled trial. J Res Med Sci. 2013;18(Suppl 1):S43–6. 49. Vallée JN, Feydy A, Carlier RY, Mutschler C, Mompoint D, Vallée CA. Chronic cervical radiculopathy: lateral-approach periradicular corticosteroid injection. Radiology. 2001;218(3):886–92. https://doi. org/10.1148/radiology.218.3.r01mr17886.

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4

Lower Extremity Disorders in Esports Caitlin McGee

4.1

General

While gamers rely on their lower extremities to a considerably lesser degree than their traditional sport counterparts, they still remain susceptible to certain disorders. Unlike the upper extremity, lower extremity injuries in esports are less commonly the result of repetitive microtrauma and more commonly the result of prolonged and sustained seated positioning. Given that gamers are significantly more conscious of the importance of their hands, one of the primary barriers to treatment of lower extremity injuries and disorders in the competitive gaming population is a lack of understanding. Education is a crucial component of any rehabilitation program, but particularly so here. A thorough understanding of the provoking factors – How long does the player sit for? On what surface? What activities do they engage in outside of gaming? How often? – is also essential for appropriate intervention, which is likely to include ergonomic modification as appropriate (Chap. 5).

C. McGee (*) 1HP, Washington, DC, USA

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 L. Migliore et al. (eds.), Handbook of Esports Medicine, https://doi.org/10.1007/978-3-030-73610-1_4

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4.1.1 Anatomy The lower extremity includes structures from the hip to the tips of the toes. In this text, “thigh” will be used to refer to the region between the knee and the hip, while “lower leg” will be used to refer to the region between the knee and the ankle. Each lower limb consists of 30 bones, the majority of which (26 in total) are located in the foot and ankle. The bones of the thigh and lower leg are the femur, patella, tibia, and fibula. The femur articulates proximally with the pelvis at the hip and distally with the tibia and patella at the knee. The tibia articulates with the femur, patella, and fibula proximally at the knee and with the fibula and talus distally at the ankle, and is connected to the fibula throughout by an interosseous membrane. Blood supply to the leg stems primarily from the external iliac artery, which becomes the femoral artery after it passes the inguinal ligament at the hip, and the obturator artery. The lumbar plexus is the source of the majority of nerve supply to the lower extremity and arises from the first four lumbar nerves with some contribution from the subcostal nerve. While a number of peripheral nerves innervate the lower extremities, the sciatic, femoral, and common peroneal nerves are most at risk due to the positions sustained during gaming.

4.1.2 Evaluation While a lesser degree of understanding of specific gaming mechanics is required for lower extremity assessment, it remains absolutely key for practitioners to be cognizant of the demands of gaming with regard to duration of sitting, frequency of movement, and the “whys” of each. Given the significant amount of time spent sitting, any assessment of lower extremity pathology should also involve an assessment of ergonomics.

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4.1.2.1 History Taking Most players are aware that sitting for long periods of time is not the healthiest of behaviors. Therefore, when taking the history for lower extremity pathology, the tone of the questions asked during the evaluation is just as important as the content. Location With regard to the lower extremity, it is important to differentiate deep from superficial pain in order to most accurately identify the structures involved. Deep pain may be more difficult to localize, whereas superficial pain can often be pinpointed with only one finger. Onset A player may not notice pain until at the end of a gaming session or when pain becomes significant enough to require a break. Often, pain is normalized and accepted as an expected consequence of prolonged sitting. Recent changes in intensity, duration, or frequency of play, modifications to a player’s gaming setup, and non-gaming activities should also be considered. Palliation and Provocation Does pain begin as soon as a player sits down, or does it worsen over time? Does pain occur with any other activities? Do transfers, such as sitting to standing or vice versa, cause more pain, or does a change of position relieve it? Quality “Burning” is a descriptor most commonly associated with nerve pain, but may also be applied to tendon pain. “Electric” and “radiating” are slightly clearer indicators of nerve involvement, although with prolonged nerve irritation, players may experience deep, achy, or cramping pain as well as fatigue and heaviness. Postural muscle injuries may be described as “achy,” “stiff,” or “sore,” while sequelae in the more distal joints may be sharper, for example, sharp lateral knee pain with iliotibial (IT) band ­syndrome.

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Radiation When assessing for potential nerve involvement, it is important to consider both dermatomal (Fig. 3.3) and peripheral nerve (Fig. 4.1) distributions. Radiation that follows dermatomal lines may be related to spinal nerve pathology. Pain that remains local without radiation is less likely to be nerve-related and more likely to involve musculotendinous structures. Esports History While the specific mechanics of a player’s game may not be relevant, an understanding of a player’s schedule with regard to daily practice, tournaments, and any streaming obligations will give a clearer picture of their demands.

4.1.2.2 Physical Examination Inspection Subtle clues and diagnostic details can be glimmered from simple inspection. The area should be completely exposed to allow for thorough evaluation. Inspection can reveal things such as swelling, erythema, and deformity. Palpation Examiners should take care to move from areas of decreased to increased tenderness. Starting in an area of maximal symptoms may lead to guarding and hamper further investigation. Palpation is useful for identifying inflammation, muscle tension, and recreating pain. Range of Motion Both active and passive range of motion (ROM) should be assessed to differentiate between musculotendinous and non-­ musculotendinous injuries, as well as to identify compensations or functional limitations resulting from the disorder. Sensory Examination As stated above, an understanding of dermatomal versus peripheral distributions is valuable for differentiating lumbar and lower extremity pathologies.

Deep peroneal Nerve L4-L5

Common Peroneal Nerve (Sural cutaneous branch) S1-S2

Superficial peroneal Nerve L4-S1

Femoral Nerve (Saphenous branch) L3-L4

Common peroneal Nerve L2-L3

Femoral Nerve (Anterior cutaneous branch) L2-L3

Femoral Nerve L2-L3

Genitofemoral Nerve L1-L2

Sciatic Nerve (Sural branch) S1-S2

Superficial peroneal Nerve L5-S1

Femoral Nerve (Saphenous branch) L3-L4

Common peroneal Nerve L5-S1

Femoral Nerve (Cutaneous branch) L2-L3

Femoral Nerve (Posterior branch) S1-S3

Femoral Nerve (Cutaneous branch) L2-L3

Last Thoracic Nerve T12

Sciatic Nerve (Tibial branch) S1-S2

Middle Cluneal Nerve S1-S3

Fig. 4.1  Peripheral sensory nerves of the lower extremity and their corresponding areas of innervation

ANTERIOR VIEW

Sural Nerve

Superficial Peroneal Nerve

Deep Peroneal Nerve

Common Peroneal Nerve

Femoral Nerve (Saphenous branch)

Obturator Nerve

Femoral Nerve

Lateral Cutaneous nerve of the thigh

lliohypogastric Nerve L1

Cluneal Nerve L1-L3

POSTERIOR VIEW

Tibial Nerve

Sural Nerve

Common Peroneal Nerve

Tibial Nerve

Sciatic Nerve

Posterior cutaneous Nerve of the thigh

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Motor Examination Manual muscle testing is useful not only for identifying muscular imbalances, but also for differentiating underlying causes. Manual muscle testing should always be performed bilaterally, even if symptoms are only unilateral, in order to establish a baseline level of strength. Reflex Examination Deep tendon reflexes can be elicited by briskly tapping the tendon of a partially stretched muscle. A vital part of the neurological examination, abnormal findings can be used to help pinpoint potential injury levels.

4.1.3 Treatment 4.1.3.1 Therapeutic Modalities Thermal modalities are commonly utilized to address pain as they are readily accessible in a home treatment setting. Ice is primarily used by the general public to address pain related to inflammation, while heat is used to address pain related to muscle tightness. While evidence is mixed on the use of transcutaneous electrical nerve stimulation for chronic or neuropathic pain [1], there is tentative evidence to suggest that it is an appropriate intervention for acute pain [2]. 4.1.3.2 Rehabilitation Conservative treatment should be pursued extensively prior to more aggressive interventions such as surgery. Referral to a rehabilitation professional such as a physical therapist allows for an individualized plan of care designed to address the patient’s specific deficits. 4.1.3.3 Pharmacology Topical and oral non-steroidal anti-inflammatory medications (NSAIDs) may provide pain relief, particularly in the acute phases of injury when inflammation is maximal. However, long-term usage can cause gastrointestinal and kidney issues. For ­neuropathic

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conditions, anticonvulsant or antidepressant may be more effective.

4.1.3.4 Interventions On the spectrum between conservative rehabilitation measures and surgical intervention, treatments such as corticosteroid injections, regenerative medicine injections, nerve blocks, and radiofrequency ablation fall somewhere in the middle. Current best practice guidelines recommend use of ultrasound guidance for injections and nerve blocks. In the long term, repeated steroid injections may damage healthy tissues and cause degeneration of cartilaginous structures. Therefore, regenerative medicine injections such a prolotherapy or platelet-rich plasma (PRP) are being considered more often.

4.2

Deep Vein Thrombosis

DVT, Venous Thromboembolism.

4.2.1 Overview Deep vein thromboses (DVTs) have historically been correlated with periods of prolonged immobility due to debility or postsurgical states. Gaming populations are at elevated risk for this condition as a result of long gameplay sessions. Chang et al. reported in 2013 on a case of deep vein thrombosis in a gamer, and several other cases of gaming DVTs have been identified [3]. Most notably, Geoff Robinson, one of the founding figures of Starcraft, was diagnosed with a DVT and later died of a pulmonary embolism.

4.2.2 Pathogenesis Thromboses can occur in any vein but the risks of prolonged sitting primarily impact those of the lower extremity. The most commonly affected veins are the femoral, popliteal, posterior tibial,

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and peroneal veins [4]. Prolonged immobility decreases the pumping action of the muscles of the lower extremities, which stagnates venous return. This muscle action is necessary due to the lower pressure gradient of the veins in the lower extremities. DVTs can occur in both healthy and unhealthy individuals who sit for prolonged periods, but there are a number of factors which elevate an individual’s risk, including: • • • • • • • • • • • •

Smoking Dehydration Long air travel Blood clotting disorders Obesity Recent injury/surgery to the region Pregnancy Use of certain oral contraceptives Use of certain hormone replacement therapies Cancer Heart failure Acute inflammatory bowel diseases

4.2.3 Presentation Unilateral DVTs are significantly more common than bilateral diagnoses. Patients may present with pain, a sensation of pressure, redness, inflammation, warmth near the site of thrombosis, coolness distal to the site of the thrombosis, and fatigue.

Pulmonary Embolism Warning Signs

A pulmonary embolism (PE) is a serious complication of a DVT that occurs when the clot migrates to vessels of the lungs. Warning signs of a PE include:

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Sudden shortness of breath without exertion Sudden increased heart rate without exertion Pain/pressure in chest, especially with deep breaths Hemoptysis Dizziness/fainting

4.2.4 Diagnosis Initial screening is often performed according to the Wells Criteria [5, 6]. This criteria tallies susceptibilities, signs, and symptoms and is shown in Table 4.1. The Wells tool is validated for use in outpatient and trauma patients. It cannot be used to screen for upper extremity DVT. Depending on availability of testing and suspected thrombosis location, duplex ultrasonography, compression ultrasonography, or color Doppler imaging may be used. In addition to venous Table 4.1  Wells clinical decision tool [5, 6] Criteria Active cancer: ongoing treatment, within previous 6 months, or palliative Paralysis, paresis, or recent immobilization of LE Recently bedridden for >3 days or major surgery within 4 weeks Localized tenderness along deep venous system distribution assessed by firm palpation in posterior calf, popliteal space, and along femoral vein in anterior thigh and groin Entire LE swelling Calf swelling >3 cm compared to asymptomatic LE, measured 10 cm below tibial tuberosity Pitting edema Collateral non varicose superficial veins Alternative diagnosis as likely or greater than that of proximal DVT (cellulitis, calf strain, Baker cyst, postoperative swelling) Tally total points. The probability of a patient having a DVT is: 0: low 1–2: moderate >3: high

Points 1 1 1 1

1 1 1 1 −2

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ultrasound, a D-dimer test may be conducted. Given the test’s high negative likelihood ratio, it is best used to rule out DVT in patients with low probability per Wells criteria. Contrast venography is considered the most accurate “gold standard” test for diagnosing blood clots. However, given the invasiveness of this procedure and the reliability of other tests, diagnosis is usually made with a combination of ultrasonography and D-dimer blood tests [4].

4.2.5 Treatment 4.2.5.1 Prevention In many cases, and particularly in the relatively young and healthy gaming population, preventive measures significantly reduce the incidence of DVTs and the subsequent need for intervention. Frequent movement is the lowest effort, easiest-to-implement preventive feature. In gamers, this takes the form of not only regular exercise but also regular breaks during gameplay [3, 7]. For individuals at elevated risk, use of compression stockings, ­pneumatic compression sleeves, or long-term anticoagulants may be used. 4.2.5.2 Intervention Anticoagulants are the primary interventional treatment for acute DVT. Anticoagulants may be injected (e.g., unfractionated or low molecular weight heparin, enoxaparin) or taken orally (e.g., warfarin, apixaban). After initial acute treatment, patients are usually placed on a maintenance course of warfarin or other Vitamin K inhibitor [8]. Thrombolytics, or “clot busters,” are sometimes used to treat more extensive thromboses. They are associated with both improved outcomes and increased risk of serious bleeding complications [9]. In individuals for whom anticoagulant therapy is contraindicated, an inferior vena cava (IVC) filter may be placed to mitigate risk of pulmonary embolism [10].

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129

Lower Crossed Syndrome

Unterkreuz syndrome

4.3.1 Overview Lower crossed syndrome refers to a pattern of muscle imbalances in the lower trunk and proximal lower extremities. It is important to note that imbalances in and of themselves may not be pathological, but rather may lead to pain or functional deficits.

4.3.2 Pathogenesis Lower crossed syndrome is characterized by weakened rectus abdominis, obliques, and gluteal muscles with tightened erector spinae, multifidi, quadratus lumborum, latissimus dorsi, iliopsoas, and tensor fascia latae [11, 12]. Hamstrings may also be tight due to increased compensatory activity. This condition is associated with prolonged periods of sitting. Sitting with the thighs flexed at the hip joint results in adaptive facilitation and tightening of the hip flexors; maintaining forward lean requires isometric contraction of the low back extensor musculature resulting in the same. Furthermore, decreased functional usage of the anterior abdominal wall and gluteal muscles result in adaptive inhibition of these muscles.

4.3.3 Presentation Lower crossed syndrome is often identified secondary to complaints of low back, hip, and/or knee pain. As a result of the muscle imbalances described above, patients will present with anterior pelvic tilt and lumbar hyperlordosis on observation. This results in a posterior shift of the center of mass, often compensated for with increased thoracic kyphosis (and, potentially with ­corresponding upper crossed syndrome). Additional compensa-

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tory movements include lateral lumbar shift, hip external rotation, and knee hyperextension.

4.3.4 Diagnosis Diagnosis for lower crossed syndrome is primarily achieved through clinical examination. Postural analysis is key to identification of lower crossed syndrome. Patients should be observed both in erect standing and during ambulation for the above postural abnormalities. Manual muscle testing of the hip extensors and hip abductors will assist with identification of compensatory mechanisms, particularly increased paraspinal activity to compensate for decreased gluteus maximus strength and increased tensor fascia latae/iliopsoas activity to compensate for decreased gluteus medius strength. This results in hip lateral rotation and flexion with abduction testing. Clinical tests for lower crossed syndrome are shown in Table  4.2. The Thomas test should be used to assess hip flexor flexibility while a straight leg raise assessment should be used to assess hamstring flexibility. The Trendelenburg test should also be used to assess glute function and hip stability.

4.3.5 Treatment Treatment for lower crossed syndrome addresses two fundamental categories. Effective strategies must not only directly address muscle imbalances, but also subsequent lifestyle changes. Generally, muscles identified as inhibited should be strengthened and muscles identified as overly facilitated should be inhibited. Stretching of tight muscles without strengthening of weakened muscles will result in minimal, if any, change. Further, passive stretching alone is less effective than active stretching to increase ROM in the lower extremity [13]. Stretching exercises should be coupled with core stabilization exercises, strengthening of the gluteal muscles, and propriocep-

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Table 4.2  Clinical tests for lower crossed syndrome Clinical test Thomas test

Straight leg raise

Trendelenburg (stance)

Description Patient supine. Bring both legs into hip and knee flexion, drawing the knee to the chest until the patient achieves neutral pelvic positioning. Passively lower the affected leg into extension until anterior pelvic tilt occurs, then assess whether patient is able to achieve hip extension or remains flexed. Patient supine. Keep non-testing leg straight and in contact with table. Passively elevate testing leg, maintaining full knee extension, until significant resistance is met, non-testing begins to lift off of table, or knee begins to flex. Measure degree of hip flexion. This test should not be confused with a Straight Leg Raise Test for nerve root sensitivity (Lasègue’s sign). Patient stands on one leg. Observe pelvic positioning. Test is positive for weakness on stance leg if patient’s pelvis is higher on the stance leg than on the non-stance leg (uncompensated) OR if patient’s pelvis is lower on the stance leg than on non-stance leg (compensated).

tive and neuromuscular re-education. This is best accomplished with the assistance of a trained physical therapist. Passive Versus Active Stretching

Active stretching involves the contraction of agonist muscles to stretch antagonist muscles. Passive stretching relies on an external force to create a stretch, such as the use of a stretching strap or assistance from a partner.

4.4

Proximal Hamstring Tendinopathy

4.4.1 Overview Most proximal or insertional hamstring tendinopathy injuries develop as a result of running and activities involving rapid deceleration and sharp pivots. However, they may also develop as a result of prolonged periods of sitting.

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4.4.2 Pathogenesis The most common cause of proximal hamstring tendinopathy is repetitive hamstring contraction while the hip is flexed, resulting in higher tensile and compressive loads at the insertion of the hamstring. Other causes of hamstring tendinopathy include excessive static stretching and prolonged sitting [14]. A number of factors elevate an individual’s risk for hamstring tendinopathy, including joint laxity, decreased flexibility, tight/ weak hamstrings and quadriceps, poor lumbopelvic/core stability, and poor proprioception.

4.4.3 Presentation Patients will present with a gradual onset of deep buttock and posterior thigh pain that is provoked with long periods of sitting, deep hip flexion, and stretching. As with other tendon injuries, in the acute phase, this presents as worse at onset of activity, improving with some degree of warm-up, and then once again worsening with increased activity. Patients may experience weakness as a result of pain-related muscle inhibition. Patients are unlikely to experience pain with walking, standing, or lying. Prolonged sitting and repetitive motions requiring a higher degree of loading, like running, are likely to increase pain.

4.4.4 Diagnosis A number of pain provocation clinical tests (Table 4.3) have been developed to aid the clinician in making an accurate diagnosis of proximal hamstring tendinopathy, including the bent-knee stretch test and the Puranen-Orava test. These tests have high sensitivity and specificity per reliability and validity testing. Palpation of the ischial tuberosity can also contribute to clinical diagnosis of proximal hamstring tendinopathy [15, 16].

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Table 4.3  Clinical tests for hamstring tendinopathy Clinical test Description Bent-knee Patient supine. Passively bring testing leg into maximal hip stretch test and knee flexion. Maintain hip flexion while extending knee passively. A positive test is indicated by posterior thigh pain that worsens as knee is further extended Puranen-­ Patient stands next to table or bench, raises leg into hip and Orava test knee flexion, and places heel of testing leg on that surface. Patient then straightens knee and reaches toward toe. A positive test is indicated by posterior thigh pain that worsens as knee is further extended.

Differential Diagnosis

The differential diagnosis for hamstring tendinopathy includes referred lumbar spinal pain, piriformis syndrome, chronic compartment syndrome of the posterior thigh, and ischiofemoral impingement. When the diagnosis is unclear, musculoskeletal ultrasound or Magnetic Resonance Imaging (MRI) can show tendon thickening, tearing, and inflammation.

4.4.5 Treatment Principles of progressive loading are an important component of the treatment plan for proximal hamstring tendinopathy. Patients should begin with isometric hamstring loading in a neutral hip position, followed by progression to isotonic loading in a minimally flexed position, and finally isotonic loading in 70–90° of hip flexion. In the early phase of recovery, hamstring stretching, trunk flexion, and repeated lifting should be avoided [17, 18]. It is important to note that while passive treatments including modalities and soft tissue mobilization may be used to alleviate pain, they will not improve load capacity and should only be used to complement or supplement more active interventions [19].

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Load modification and ergonomic changes are also key to recovery from tendinopathy. Patients who sit for prolonged periods may benefit from the use of a shaped cushion to offload the irritated area. Shaped Cushions for Hamstring Tendinopathy

For proximal hamstring tendinopathy, a cushion can be used to offload the proximal hamstring tendon. This can either be a pillow with additional bulk in the front, putting more pressure on the hamstring muscle belly, or a shaped ergonomic pillow that is contoured to the shape of the thighs and buttocks. Research is mixed on the value and efficacy of NSAIDs with regard to tendon injuries. While NSAIDs can decrease pain and inflammation, they may also inhibit tendon healing. When conservative treatment is insufficient, a corticosteroid injection into the soft tissues surrounding the tendon may be beneficial with regard to pain and inflammation. This has been shown to be more effective in patients with less severe tendon thickening [20]. However, corticosteroid injections can result in weakening of load-bearing tendons and are not a long-term solution; they are most beneficial when used in conjunction with physical therapy for progressive loading. Injection of platelet-rich plasma or prolotherapy has also been proposed as a potential alternative to corticosteroid injections to promote tissue healing; however, there is insufficient evidence to support their widespread use at this time.

4.5

Piriformis Syndrome

Extra-spinal sciatica, deep gluteal syndrome, wallet neuritis.

4.5.1 Overview Piriformis syndrome is a musculoskeletal condition in which peripheral branches of the sciatic nerves are irritated by an abnormal condition of the piriformis muscle.

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4.5.2 Pathogenesis The most common anatomical relationship between the piriformis and sciatic nerve involves the sciatic nerve exiting the greater sciatic foramen along the inferior surface of the piriformis. Documented anatomical variations from this course include the sciatic nerve passing through the piriformis, superiorly to the piriformis, or the tibial branch splitting from the main portion of the sciatic nerve and passing either inferiorly or superiorly to the piriformis separately from that main branch. It was previously thought that these variations may predispose to a higher risk of piriformis syndrome. However, research has not found a significant difference in the prevalence of anomalous anatomical variations in patients with piriformis syndrome relative to the prevalence in the uninjured population [21]. Despite this shift in understanding, piriformis syndrome in which an anatomical variation of the sciatic nerve is identified is referred to as primary piriformis syndrome. Secondary piriformis syndrome is the result of some external cause like muscle spasms secondary to lumbar or sacroiliac pathologies, altered biomechanics of the low back and pelvic regions, microtrauma from direct compression (i.e., “wallet neuritis”) or overuse, or macrotrauma to the buttocks resulting in soft tissue inflammation . Rarer causes of piriformis syndrome may include bursitis of the piriformis, colorectal carcinoma, episacroiliac lipoma, Klippel-­Trenaunay syndrome, abscess or hematoma, neoplasms in the area of the infrapiriform foramen, irritation following intragluteal injection, and myositis ossificans of the piriformis muscle. Piriformis syndrome is more common in women due to the wider angle of the quadratus femoris in the pelvic girdle.

4.5.3 Presentation Patients often complain of a pressure like pain in the buttocks. This may radiate down the posterior thigh with resulting paresthesia and pain-related inhibition may be present. Patients frequently

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report irritation with prolonged sitting or walking, squatting, and positions that increase the tension of the piriformis muscle, such as hip adduction and internal rotation. Patients may also demonstrate a “splayfoot sign” with hip external rotation during standing, walking, or lying in supine [22].

4.5.4 Diagnosis Piriformis syndrome may be diagnosed via clinical testing or with diagnostic injections.

4.5.4.1 Physical Examination Clinical testing of piriformis syndrome should include palpation of the greater sciatic notch and of the piriformis muscle belly. Deep palpation of the retro-trochanteric region may elicit leg numbness and an exacerbation of tightness [23]. With most cases, there is no loss of deep tendon reflexes or weakness in a myotomal pattern. A number of clinical assessments (Table 4.4) are also valuable for identifying piriformis syndrome and differentiating it from other, similar conditions. Differential Diagnosis

Differential diagnosis of piriformis syndrome includes trochanteric bursitis, lumbosacral radiculopathies or facet syndromes, sacroiliac pathologies, lumbar spinal stenosis, referred pain from pelvic visceral malignancies or diseases of the appendix and renal system, and intra-articular hip pathologies. Beatty’s maneuver in particular is useful for distinguishing between piriformis syndrome and lumbar discogenic pain, as patients with piriformis syndrome will experience deep buttock pain while patients with lumbar discogenic issues will experience back and leg pain [24].

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Table 4.4  Clinical tests for piriformis syndrome Clinical test Description Pace’s sign Position patient in sitting with testing leg in abduction and external rotation, then apply resistance. A positive result is indicated by pain with resisted abduction and external rotation. Straight leg Patient supine. Passively raise testing leg. A positive result is raise test indicated by recreation of radiating LE pain. Freiberg Patient supine. Passively bring leg into maximal internal hip sign rotation. A positive result is indicated by recreation of radiating LE pain. FADIR test Position patient in sidelying with testing leg on top. Passively bring leg into 90 degrees of hip flexion, adduction, and internal rotation. A positive result is indicated by pain in the gluteal region. Position patient in sidelying with testing leg on top. Beatty’s maneuver Passively bring leg into 90 degrees of hip flexion. Instruct patient to perform abduction, and resist patient’s attempt. A positive result is indicated by pain in the buttock region.

4.5.4.2 Imaging and Diagnostics The role of further diagnostics is limited, as imaging is more useful for ruling out other conditions. Ultrasound-guided injections may be used for therapeutic as well as diagnostic purposes.

4.5.5 Treatment Conservative treatment methods are the mainstay of effective treatment [25]. Pharmacological agents can be utilized for pain control, such as NSAIDs, muscle relaxants, and neuropathic pain medications. When pain is appropriately managed, physical therapy and lifestyle modifications can be instituted to promote recovery. Physical therapy should include strengthening of the hip extensors, abductors, and external rotators; soft tissue mobilizations; and piriformis stretching. Lifestyle modifications may include increasing frequency of standing/walking breaks while sitting every 20 min, incorporating daily stretching, and making stops during long drives to stand and change position.

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Ultrasound-guided injections of the piriformis with anesthetics, corticosteroid, or chemodenervation may address cases refractory to conservative management. Surgical interventions such as tenotomy of the piriformis tendon or release of the internal obturator muscle should only be considered with intractable, disabling symptoms for which a trial of conservative management has failed. Additional indications for surgical intervention include the presence of an abscess, neoplasm, hematoma, or painful vascular compression from gluteal varicosity.

4.6

Sacroiliac Joint Pathology

SIJ dysfunction, Sacroiliitis.

4.6.1 Overview Sacroiliac (SI) joint pathologies result in back pain that may be misdiagnosed as radicular lumbar pain and subsequently mistreated by clinicians. This condition is remarkably common, and contributes to 10–27% of low back pain cases [26].

4.6.2 Pathogenesis The primary function of the sacroiliac joints is load transfer between the spine and lower extremities, which requires a balance of mobility and stability mediated both passively by ligamentous structures and actively by muscular attachments on the sacrum and innominate bones. Dysfunction of any of these structures can result in SIJ pathology. The most straightforward causes of sacroiliac joint dysfunction result from direct trauma to the region, as in a motor vehicle accident, and the release of relaxin during pregnancy resulting in increased ligamentous laxity.

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SI joint dysfunction is more common in obese individuals and individuals who lead sedentary lifestyles. This likely reflects a number of factors including postural strain on the passive ligamentous structures supporting this region and decreased active support secondary to decreased muscular strength and endurance.

4.6.3 Presentation Symptoms of SI joint dysfunction are very similar to symptoms of other types of low back pain, which may confound diagnosis. In fact, “low back pain” is the most commonly reported symptom associated with SI joint dysfunction. This pain may be localized to the posterior aspect of the joint or refer down the posterior thigh, usually not past the knee. Pain will worsen with mechanical stress of the SI joint, as during forward trunk flexion or stair ascent/descent.

4.6.4 Diagnosis Given the similarity in symptoms between this pathology and other types of low back pain, any diagnosis of SI joint dysfunction must include mechanisms to rule out other potential causes.

4.6.4.1 Physical Examination Differential Diagnosis

The differential diagnoses for SI joint pathology includes radicular pain, piriformis syndrome, ankylosing spondylitis, lumbosacral facet syndrome, spondyloarthropathy, and trochanteric bursitis. Most diagnoses are made with a combination of ruling out other back pain sources and ruling in SI joint dysfunction using provocative clinical tests [27]. No single test has a particularly high sensitivity or specificity, and are subsequently used in

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Table 4.5  Clinical tests for SI joint dysfunction Clinical test Description Gaenslen test Position patient in supine with testing leg at edge of the table, almost off the side. Patient holds non-testing leg in hip and knee flexion. Passively abduct testing leg just enough to lower into hip extension with knee flexion off the side of the table. Apply hyperextension overpressure to testing leg and flexion overpressure to non-testing leg. A positive test is indicated by reproduction of the patient’s pain. Sacral thrust Patient prone. Apply anterior pressure to center of sacrum to create shear force across both SI joints. A positive test is indicated by reproduction of pain in sacroiliac region. Position patient in sidelying. Apply downward pressure on SI joint compression superior iliac crest, directing force at opposite iliac crest. A positive test is indicated by reproduction of pain in test sacroiliac region. Patient supine. Apply posterolateral pressure to bilateral SI joint anterior superior iliac spine. A positive test is indicated by distraction reproduction of pain. test FABER test Patient supine. Place patient in “Fig. 4” position with hip in flexion and abduction, knee in flexion, and lateral ankle resting on opposite thigh proximal to the knee. Stabilize the opposite side of the pelvis at the anterior superior iliac spine, then apply a posterior force to the knee of the testing leg. A positive test is indicated by reproduction of pain or limited range of motion relative to the contralateral leg. Yeoman test Patient prone. Passive flex the knee of the leg to be tested to 90 degrees. Stabilize the ipsilateral pelvis and passively extend the hip of the testing leg. A positive test is indicated by pain in the SI joint.

c­ ombination with others. As such, clinicians should use at least three tests shown in Table 4.5 to make an accurate diagnosis [28].

4.6.4.2 Imaging Computerized tomography (CT) and MRI are useful primarily as “rule-out” diagnostic tools to identify arthritis, multiple myeloma, stenosis, bursitis, fracture, herniation, or tendinopathy. As with piriformis syndrome, ultrasound-guided injection is valuable both as a diagnostic and therapeutic tool, particularly in patients with

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isolated and localized pain or patients with positive results on a cluster of clinical tests [29, 30].

4.6.5 Treatment Best outcomes in the treatment of SI joint dysfunction result from a multidisciplinary care model. With physical therapy, treatment should involve reducing inflammation if present, addressing hypomobility with joint mobilization/manipulation, and addressing hypermobility or instability with core stabilization and motor control exercises. Patients should also receive education in postural and ergonomic modifications [31]. In patients for whom chronic low back pain has developed as a result of SI joint dysfunction, ablation of the nociceptive nerve fibers may be appropriate [32].

4.7

 ompressive Neuropathies of the Lower C Extremity

4.7.1 General 4.7.1.1 Overview While compressive neuropathies of the upper extremity, such as carpal tunnel syndrome or radial tunnel syndrome, are more common and certainly more well-known in the general population, compressive neuropathies of the lower extremity remain an important consideration for gaming populations. In this section, we explore the three nerves most at risk in the esports population. 4.7.1.2 Pathogenesis Nerve entrapment most commonly occurs in anatomical regions where the nerve passes by or through another structure, such as a fascial opening, a bony groove or fissure, or a muscle belly. Pressures as low as 20 mm Hg are enough to affect signal transmission along a nerve, with higher pressures resulting in more

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significant blocks to nerve conduction. As a general rule, the longer and more significant the compression, the longer the recovery. Nerve entrapments may be broadly divided into three stages [33]. • Stage I: Intermittent paresthesias and sensory deficits, most commonly at night • Stage II: Dexterity and endurance are impacted and symptoms become consistent • Stage III: Morphological changes, such as segmental demyelination and increased edema, occur

4.7.1.3 Diagnosis A thorough history taking is essential, including knowledge of a player’s preferred postures and points of potential compression resulting from their gaming ergonomics. As emphasized previously, knowledge of dermatomal and peripheral nerve distributions is key to identifying the origin of nerve-related pathology. Ultrasonography, electrophysiological testing, and advanced imaging may also be of diagnostic importance in severe or unclear cases [34, 35]. 4.7.1.4 Treatment Appropriate interventions for these conditions fall into two categories: symptomatic care and preventive care. Symptomatic care focuses on mitigating pain and can include therapeutic exercise, bracing, manual therapy, injections, and NSAIDs or neuropathic pain medications. These should be designed to address a player’s specific symptoms. Preventive care involves first identifying the factors originally leading to compression, such as posture, type or size of chair, provoking activities, or even restrictive clothing. Once provocations have been determined, interventions to remove them can be instituted. This may involve ergonomic changes or activity modification.

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4.7.2 Common Peroneal Nerve 4.7.2.1 Overview Peroneal neuropathy is the most common lower extremity compressive neuropathy [36]. The common peroneal nerve originates centrally from fibers of the L4-S1 nerve roots and branches peripherally off of the sciatic nerve above the popliteal fossa, providing motor innervation to ankle everters, ankle dorsiflexors, and toe dorsiflexors and providing sensory innervation to the lateral lower leg and the dorsum of the foot. It is vulnerable to compression due to its positioning against the fibular head. Risk factors for this condition include positions of prolonged knee flexion, positions involving prolonged leg crossing, and low bodyweight [37]. Fibular Versus Peroneal

A long-standing debate between anatomists and clinicians, the two terms refer to identical structures.

4.7.2.2 Presentation The characteristic hallmark of this compressive neuropathy is foot drop. Prior to this development, players may complain of numbness over the lateral lower leg and dorsum of the foot, or paresthesia radiating down the sensory distribution. 4.7.2.3 Diagnosis Patients should be questioned about potential risk factors, such a propensity to cross the legs. On examination of a patient’s gait, foot drop may be noticed. Manual muscle testing can reveal weakness in the muscles innervation by the common peroneal nerve, as well as numbness in the sensory distribution. Abnormal deep tendon reflexes of the quadriceps or Achilles tendons support a more proximal diagnosis. Nerve conduction testing and needle electromyography are appropriate diagnostic modalities and may also provide insight into the severity of injury.

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Differential Diagnosis

Foot drop may also occur with sciatic nerve injury, lumbosacral nerve injury, or L4-S1 radiculopathy.

4.7.2.4 Treatment As with other lower extremity compressive neuropathies, conservative management including physical therapy, activity, and ergonomic modification, and bracing are appropriate interventions. Surgical intervention is rarely required and generally not recommended.

4.7.3 Sciatic Nerve 4.7.3.1 Overview The sciatic nerve is the largest nerve in the human body. It originates centrally from fibers of the L4-S3 nerve routes. It passes through the pelvis and into the gluteal region at the greater sciatic foramen and exits either under, through, or around the piriformis muscle. From there, it courses between the gluteus maximus and the quadratus femoris, and runs between the hamstrings and the adductor magnus until it divides into the common peroneal and tibial nerves just above the popliteal fossa. Compression may result from prolonged sitting or pressure, female sex, hamstring injury, or piriformis hypertrophy [23, 38, 39]. Wallet Neuritis

Individuals who consistently wear their wallet in their rear pocket on the same side and do not remove it prior to sitting may develop direct sciatic nerve irritation.

4.7.3.2 Presentation Players may complain of numbness, tingling, and pain in the buttock and posterior-lateral leg. With prolonged compression, radiation may occur as far as the knee.

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4.7.3.3 Diagnosis As with other peripheral neuropathies, this condition must be differentiated from lumbar radiculopathies and facet arthropathies. Clinical diagnosis should, therefore, include a neurological examination of the lower limb, palpation at potential sites of entrapment for provocation, and use of the straight leg raise test to elicit LaSegue’s sign. It is important to note that while this test has high sensitivity, it has low specificity [40]. LaSegue’s sign alone is not sufficient for a diagnosis of sciatic nerve entrapment. Clinical examination may be combined with electrodiagnostic studies, MRI, or diagnostic injection. 4.7.3.4 Treatment Treatment is dependent on the location of the site of entrapment. Conservative interventions including therapeutic exercise, modalities, and soft tissue or joint mobilization form the first line of defense. Ultrasound- or fluoroscopic-guided injection may be performed for therapeutic as well as for diagnostic purposes. In cases occurring as a result of hip fracture or compartment syndrome, or in patients who have not experienced significant improvement following conservative interventions, surgical release of the nerve may be appropriate [41].

4.7.4 Femoral Nerve 4.7.4.1 Overview Femoral compressive neuropathy is less common than either sciatic or peroneal entrapments and most commonly occurs secondary to surgery [42]. The femoral nerve is derived centrally from the L2-L4 nerve roots. It passes under the inguinal ligament to enter the anterior thigh and immediately divides into anterior and lateral divisions to provide sensory and motor innervation to the anterior thigh.

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4.7.4.2 Presentation The primary symptom of femoral nerve entrapment is weakness of the quadriceps muscle. Players with compressive neuropathy occurring above the inguinal ligament will present with hip flexor weakness, while players with compressive neuropathy occurring below the inguinal ligament will not. 4.7.4.3 Diagnosis When examining players for this condition, consider if their motor and sensory deficits match the sensory distribution of the femoral nerve (anterior and medial thigh sensation) or if other nerve distributions are involved (e.g., lateral thigh sensation from the obturator nerve). Severe injury may result in patellar tendon reflex deficits. The modified Thomas Test, with combined hip extension and knee flexion, is likely to recreate symptoms [43]. To perform this test, position the patient in supine with hips at the very end of the table. The patient should hold the non-testing leg in maximal knee and hip flexion, allowing the testing leg to hang freely. This test is primarily used to assess deficits in the quadriceps, rectus femoris, psoas, or tensor fascia lata muscles, but may also result in recreation of pain in patients with femoral nerve entrapment. Nerve conduction studies are of limited utility for diagnosis of femoral nerve entrapment, as only the portions distal to the inguinal ligament can be assessed via traditional techniques. Ultrasound or MRI may be appropriate when an injury proximal to the inguinal ligament is suspected [44]. 4.7.4.4 Treatment Manual therapy, therapeutic exercise, stretching, ergonomic changes, injections, and education are all appropriate components of a conservative intervention plan [45]. Surgical interventions such as neurolysis or neurectomy should only be considered when symptoms fail to respond well to conservative management.

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12. Janda V. Muscles and motor control in low back pain: Assessment and management. In: Twomey LT, editor. Physical therapy of the low back. New York/Edinburgh/London: Churchill Livingston; 1987. p. 253–87. 13. Roberts J, Wilson K. Effect of stretching duration on active and passive range of motion in the lower extremity. Br J Sports Med. 1999;33(4):259– 63. https://doi.org/10.1136/bjsm.33.4.259. 14. Lempainen L, Sarimo J, Matilla K, Orava S. Proximal hamstring tendinopathy – overview of the problem with emphasis on the surgical treatment. Oper Tech Sports Med. 2009;17:225–8. https://doi.org/10.1053/j. otsm.2009.12.016. 15. Lempainen L, Johansson K, Banke IJ, et al. Expert opinion: diagnosis and treatment of proximal hamstring tendinopathy. Muscles Ligaments Tendons J. 2015;5:23–8. 16. Goom TS, Malliaras P, Reiman MP, Purdam CR. Proximal hamstring tendinopathy: clinical aspects of assessment and management. J Orthop Sports Phys Ther. 2016;46(6):483–93. https://doi.org/10.2519/ jospt.2016.5986. 17. Harvey MA, Singh H, Obopilwe E, Charette R, Miller S. Proximal hamstring repair strength: a biomechanical analysis at 3 hip flexion angles. Orthop J Sports Med. 2015;3(4):2325967115576910. https://doi. org/10.1177/2325967115576910. 18. Cook JL, Purdam CR.  Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br J Sports Med. 2009;43(6):409–16. https://doi.org/10.1136/ bjsm.2008.051193. 19. Guex K, Millet GP. Conceptual framework for strengthening exercises to prevent hamstring strains. Sports Med. 2013;43(12):1207–15. https://doi. org/10.1007/s40279-­013-­0097-­y. 20. Zissen MH, Wallace G, Stevens KJ, Fredericson M, Beaulieu CF. High hamstring tendinopathy: MRI and ultrasound imaging and therapeutic efficacy of percutaneous corticosteroid injection. Am J Roentgenol. 2010;195(4):993–8. https://doi.org/10.2214/AJR.09.3674. 21. Smoll NR. Variations of the piriformis and sciatic nerve with clinical consequence: a review. Clin Anat. 2010;23(1):8–17. https://doi.org/10.1002/ ca.20893. 22. Kirschner JS, Foye PM, Cole JL.  Piriformis syndrome, diagnosis and treatment. Muscle Nerve. 2009;40(1):10–8. https://doi.org/10.1002/ mus.21318. 23. Boyajian-O'Neill LA, McClain RL, Coleman MK, Thomas PP. Diagnosis and management of piriformis syndrome: an osteopathic approach. J Am Osteopath Ass. 2008;108(11):657–64. https://doi.org/10.7556/ jaoa.2008.108.11.657. 24. Hopayian K, Song F, Riera R, Sambandan S. The clinical features of the piriformis syndrome: a systematic review. Eur Spine J. 2010;19(12):2095– 109. https://doi.org/10.1007/s00586-­010-­1504-­9.

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25. Fishman LM, Dombi GW, Michaelsen C, Ringel S, Rozbruch J, Rosner B, Weber C. Piriformis syndrome: diagnosis, treatment, and outcome—a 10-year study. Arch Phys Med. 2002;83(3):295–301. https://doi. org/10.1053/apmr.2002.30622. 26. Raj MA, Varacallo M. Sacroiliac (SI) joint pain. In: StatPearls. StatPearls Publishing. 2019. https://www.ncbi.nlm.nih.gov/books/NBK470299/. Accessed 28 June 2020 27. Zelle BA, Gruen GS, Brown S, George S. Sacroiliac joint dysfunction: evaluation and management. Clin J Pain. 2005;21(5):446–55. https://doi. org/10.1097/01.ajp.0000131413.07468.8e. 28. Broadhurst NA, Bond MJ. Pain provocation tests for the assessment of sacroiliac joint dysfunction. J Spinal Disord. 1998;11(4):341–5. PMID: 9726305 29. D'Orazio F, Gregori LM, Gallucci M. Spine epidural and sacroiliac joints injections—when and how to perform. Eur J Radiol. 2015;84(5):777–82. https://doi.org/10.1016/j.ejrad.2014.05.039. 30. Maigne JY, Aivaliklis A, Pfefer F. Results of sacroiliac joint double block and value of sacroiliac pain provocation tests in 54 patients with low back pain. Spine. 1996;21(16):1889–92. https://doi.org/10.1097/00007632-­ 199608150-­00012. 31. Al-Subahi M, Alayat M, Alshehri MA, Helal O, Alhasan H, Alalawi A, et al. The effectiveness of physiotherapy interventions for sacroiliac joint dysfunction: a systematic review. J Phys Ther Sci. 2017;29(9):1689–94. https://doi.org/10.1589/jpts.29.1689. 32. Aydin SM, Gharibo CG, Mehnert M, Stitik TP.  The role of radiofrequency ablation for sacroiliac joint pain: a meta-analysis. Am J Phys Med Rehabil. 2010;2(9):842–51. https://doi.org/10.1016/j.pmrj.2010.03.035. 33. Flanigan RM, DiGiovanni BF. Peripheral nerve entrapments of the lower leg, ankle, and foot. Foot Ankle Clin. 2011;16(2):255–74. https://doi. org/10.1016/j.fcl.2011.01.006. 34. Petchprapa CN, Rosenberg ZS, Sconfienza LM, Cavalcanti CF, Vieira RL, Zember JS.  MR imaging of entrapment neuropathies of the lower extremity. Part 1. The pelvis and hip. Radiographics. 2010;30(4):983– 1000. https://doi.org/10.1148/rg.304095135. 35. Donovan A, Rosenberg ZS, Cavalcanti CF. MR imaging of entrapment neuropathies of the lower extremity. Part 2. The knee, leg, ankle, and foot. Radiographics. 2010;30(4):1001–19. https://doi.org/10.1148/ rg.304095188. 36. Bowley MP, Doughty CT. Entrapment neuropathies of the lower extremity. Med Clin N Am. 2018;103(2):371–82. https://doi.org/10.1016/j. mcna.2018.10.013. 37. Cruz-Martinez A, Arpa J, Palau F.  Peroneal neuropathy after weight loss. J Peripher Nerv Syst. 2000;5(2):101–5. https://doi.org/10.1046/j.1529-­8027.2000.00007.x.

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5

The Ergonomics of Esports Caitlin McGee

5.1

Neutral Posture

5.1.1 Head and Neck The head should be placed in a neutral position, with variation expected due to structural differences of the axis (C2). Cervical lordosis develops early on when infants begin to pick up their heads, and should be present in most cases. Common issues that may arise from a non-neutral head and non-lordotic cervical spine are discussed in depth in Chap. 3.

5.1.2 Trunk and Arms The natural lordotic curve of the lumbar spine should be supported. Chest should be elevated with mild scapular retraction. Arms should be supported to meet these criteria, in order of ­priority:

C. McGee (*) 1HP, Washington, DC, USA

© The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 L. Migliore et al. (eds.), Handbook of Esports Medicine, https://doi.org/10.1007/978-3-030-73610-1_5

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1. Wrists are maintained in neutral positioning or mild extension in the coronal plane, and neutral positioning or mild ulnar deviation in the sagittal plane, on mouse and keyboard. 2. Forearms are supported at the level of the navel. 3. Upper arm is supported close to the body, minimizing shoulder abduction.

5.1.3 Lower Extremities Hips should be maintained in a pelvic neutral positioning. This requires appropriate support for the feet and legs. If the feet are not adequately supported, players tend to compensate with either an anterior or posterior pelvic tilt, as shown in Fig. 5.1. With an anterior pelvic tilt, players compensate with either an accentuated lumbar lordosis or a forward trunk lean with forearm support on the thighs. A posterior pelvic tilt can cause flattening of the lumbar lordosis, and occur in tandem with a backward trunk lean and an excessive thoracic and cervical kyphosis. With the feet adequately supported, weight is distributed through the thighs as well as through the hips and buttocks, allowing for pelvic neutral positioning.

a

b

Fig. 5.1 (a) Anterior pelvic tilt, accompanied by increased lumbar lordosis. (b) Posterior pelvic tilt with flattening of the lumbar lordosis

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153

Gaming Categories

For the purpose of this section, it is important to define several categories of gaming: 1. PC 2. Console 3. Mobile Virtual Reality Ergonomics

This section will not address virtual reality (VR) gaming ergonomics. Depending on the title, VR ergonomics may be similar to the postures and positions trained for in traditional sports, for which there is an abundance of existing literature. PC games include any games played on a personal computer, most commonly using mouse and keyboard. Console games include any games played on a gaming console, such as Xbox, Playstation, Gamecube, and Wii. While devices like the Nintendo Gameboy and Nintendo Switch are considered to be consoles, for the purposes of ergonomics we will consider them to be mobile gaming devices. Mobile games are most commonly played on a smartphone, tablet, or handheld gaming device. For a more detailed description of the gaming categories and popular titles, Chap. 1 provides an in-depth analysis of the basics of esports.

5.3

Peripherals

5.3.1 Monitor Monitors should be aligned to minimize cervical flexion, extension, and rotation. In practice, the top of the monitor should be approximately level with the eyebrows. A single monitor should

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be positioned at the median line of the coronal plane; multiple monitors should be symmetrically distributed about this line [2]. Monitors should be 20–40 inches (50–100 cm) from the eyes. When monitors are too close, players are more likely to develop convergence-related eyestrain and to assume suboptimal postures, usually involving excessive thoracic kyphosis and posterior pelvic tilt. When monitors are too far, players are more likely to develop eye issues related to squinting, most commonly overuse/strain of the eye muscles and dry eye, as squinting has been shown to reduce blink rate and subsequent lubrication of the surface of the eye [3]. Too-far monitors also put players at risk of increased forward head posture and anterior pelvic tilt/forward trunk lean, reducing external support for the spine and increasing strain on the structures supporting the spine.

5.3.2 Mouse The optimal size, weight, and sensitivity of a mouse will depend heavily on both the playstyle and the biomechanics of the person using it. However, certain general principles apply across all players. A mouse that is too tall will provide increased pressure at the distal transverse arch of the palm, promoting a greater degree of wrist extension. Increased wrist extension positions the hand and finger extensors in suboptimal resting length-tension relationships; it also increases pressure in the carpal tunnel. Wrist extension greater than 30 ° increases carpal tunnel pressure by 7%, and extension greater than 45 ° creates a significantly increased risk for musculoskeletal syndromes [4]. The weight of a mouse is also relevant, particularly for players who lift and move their mouse repeatedly as a way to reposition the mouse without repositioning the pointer. This playstyle specifically benefits from a lighter mouse. Dots Per Inch (DPI) is a measure of mouse sensitivity. When DPI is lower, a player must move the mouse more to accomplish the same in-game movement as someone with a higher DPI. When DPI is higher, smaller volume movements accomplish the same

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in-game movements, but the increased precision required often results in higher sustained grip forces. No studies have indicated a clear link between higher vs lower DPI and risk of pain or injury. There are three common mouse grip styles in gaming: palm, claw, and tip as shown in Fig. 5.2. Each of these have their own ergonomic considerations.

Fig. 5.2  The most common mouse grip styles utilized while gaming

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Fig. 5.2 (continued)

In the palm grip, the majority of the hand from distal transverse arch to the base of the thenar and hypothenar eminences rests on the top and back of the mouse, while the middle and distal phalanges of two fingers – usually the second and third digits – rest on the left and right mouse buttons, respectively. This grip is most comfortable on a longer mouse with a moderate arch height, which usually correlates with a heavier weight of the mouse. It requires the least sustained contraction of wrist stabilizers but does not lend itself easily to picking up and moving the mouse. The claw grip works best on a shorter mouse with a more aggressive arch height. In this grip, the base of the palm rests on the back edge of the mouse, the distal palm and proximal and middle phalanges are unsupported, and the tips of two fingers rest on the left and right mouse buttons, with the remaining fingers stabilizing the outer edges of the mouse, causing a more “clawed” hand shape. This grip is associated with increased muscular load over time relative to a palm grip but allows for increased ease picking up and moving the mouse when not in contact with a mousepad. The tip grip provides the least passive support to the hand. In this grip, the palm is entirely elevated and only the tips of two

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fingers rest on the left and right mouse buttons, while the remaining fingers stabilize the outer edges of the mouse. This grip is associated with the greatest muscular load over time but also allows for a significant degree of precision and speed. Players using this grip should look for light, short, low-arched mice. Regardless of grip type, wrist flexion/extension and wrist ulnar/radial deviation should rest in an approximately neutral position. Mild wrist extension, up to 15 °, does not pose any additional pain or musculoskeletal injury risk; similarly, mild wrist ulnar deviation of up to 5° may be a more comfortable position for some players. Increased ulnar deviation may increase risk of injury [5].

5.3.3 Keyboard Two planes of motion of the wrist are relevant with regard to keyboard position. As with mouse position, attention must be paid to wrist flexion/extension, occurring in the frontal plane about a sagittal axis, and wrist ulnar/radial deviation, occurring in the coronal plane about a transverse axis. Both keyboard and mouse should allow for approximately neutral positioning of the wrist, with 0–15 ° of extension and 0–5 ° of ulnar deviation. Mechanical keyboards are the most common keyboard type used in gaming. A mechanical keyboard is made with spring-­ activated key switches. Different switches have different characteristics concerning their actuation, tactile, and reset points. A keyboard’s actuation point is the point at which the contact mechanism registers a key press. Tactile point is the point during the keypress at which the key provides tactile feedback to your finger that the key has been actuated, usually at the point of maximum depression. Reset points is the point at which the mechanism ceases to register the key press. Actuation force has been shown to be correlated with musculoskeletal symptoms among office-working populations, although less research has been conducted in gaming populations. Research indicates that an actuation force of